Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2
Author: Subject: Interfacing 80's UV VIS
hector_carbossa
Harmless
*




Posts: 22
Registered: 30-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 7-12-2008 at 11:36


Hi. Today I did "inverse" tests. I shorted pins already shorted when I found device plus some other combinations. I shorted port's CTS/RTS and tried two combinations of remaining pins on 2 and 3. This doesn't run.

I also tried setting port from device manager, disabling FIFO (random test) but nothing.
Thing for what I hope I'll be forgiven, it's I noted one time, when I moved wires on powered device, some activity from it.

However, regarding continuous pulse, I'm sorry but I expressed result unclearly. I have continuous signal when off and single pulse when I turn off. Sorry again.

Test with power supply may be informative if it can give back different results than previouses. I've some ATXs. Thus, I have to reset to 75 baud and connect each pin throug led and 10k one time to ground, then to +5 eventually restarting.
In effect I have only to find hardware control pins which one of then has real continuous out signal (logic O) to ground then logic 1 pin has continous in signal from +5V.

Pinout on the other side may be 7 or 8 but for a profane than me they may be DTR/DSR with same probability. Nonetheless I think crossed cable (that lost any sort of meaning long time ago) at this point may have shorted 1 and 6. Not 7 and 8 or 4 and 6 because this may had seen with programs but I'll test all connections.

Finally, the other connector seems with probability SCSI DB50 female but I don't know was it used for. "Terminal" label doesn't leave me any doubt it's printer reserved (Local Printer Terminal).
View user's profile View All Posts By User
hector_carbossa
Harmless
*




Posts: 22
Registered: 30-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 8-12-2008 at 12:33


Hi. Today I performed further high-low test on 75-110 baud connecting each pin to 10 k- antiparallel led series. These results seems to be sometime paradoxal but I implied device's feedback to each tension. However a -3V exit may have been interesting. Escaping from all possible conclusions, pins 3 and 4 seems to have similar and opposite behavior, respectively: always pulses in/out then continuous signal out/in and peculiar stepping-glowing down. My "biochemical" approach make me to say 3 and 4 nature seems different than 1 and 2.

However, I used simple resistor instead of parallel of leds-resistor/wire excluding ATX's "signal" effects on system. Anyway these effects seemed to attempt with this configuration. +/-12, -3 tests may be useful but should be too hazardous.

In addition, pulses seems to be slower at 75 baud than at 2400.

Next tests I'll try will use normal cable to have minimum influence by shorts.

Results are:
    • GND
      • ON cont. in
      • OFF

    • +5V
      • ON long single pulse in
      • OFF continue fading down out


    • GND
      • ON cont. in
      • OFF

    • +5V
      • ON pulse in
      • OFF fading down out


    • GND
      • ON pulse in then continuous out
      • OFF pulse in then pulse out

    • +5V
      • ON pulse in then cont. out
      • OFF fading down out with discrete steps


    • GND
      • ON pulse in then pulse out then continuous in
      • OFF pulse in then pulse out

    • +5V
      • ON pulse in then pulse out then continuous in
      • OFF pulse in then stepped-fading down out


View user's profile View All Posts By User
watson.fawkes
International Hazard
*****




Posts: 2793
Registered: 16-8-2008
Member Is Offline

Mood: No Mood

[*] posted on 8-12-2008 at 19:02


If you're seeing pulses that vary by baud rate setting, you've likely got data. To see if you can receive it, make a 2-wire cable to your PC--one wire for ground and the other for data. Leave the rest of the pins configured identically on the breadboard so your flow control works. See http://pinouts.ru/SerialPorts/Serial9_pinout.shtml for pinouts on the PC side, where you'll want (in the symbols of that page) RXD and GND. You might well be able to see the data it's sending with ordinary terminal software.
View user's profile View All Posts By User
hector_carbossa
Harmless
*




Posts: 22
Registered: 30-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 9-12-2008 at 15:23


Hi. No combination with CTS/RTS pins works. Perhaps I'm unable to receive data for various reasons or there's not data but only mark signal.

However, I shall connect presumable controls with DTR and DSR. I also shorted each pair trying reception but nothing appears.

A thing to clarify worth pulses: I never seen alternating light on/off but only one alternation. Nothing similar bit flow and nothing useful in discriminating a tx from a CTS or something similar. Only difference stay in behavior on the test. 3 and 4 has same on/off sequence but opposite leds (and signal) states.

At this point there's software or hardware cause. Mechanical calibrations always are performed automatically but I may confirm them are different with some combinations but this is probably madness.

Finally, having a program that shows me received data, then parity, stop and lenght may have secondary importance. The fact is there is no data. If this is due to software configuration I'll never discover correct pinout in human-friendly periods. But this seems unprobable as conseguence debug programs are made mainly to view data.

Only DSR/DTR combinations separe me to defeat or success but now I doubt.

ANOTHER THING

An additional cause in the caotic realm of presumable causes may be absence of deuterium lamp that incide on starting controls but absence of something notify this makes this hypothesis opinable.

[Modificato il 10-12-2008 da hector_carbossa]

[Modificato il 10-12-2008 da hector_carbossa]
View user's profile View All Posts By User
hector_carbossa
Harmless
*




Posts: 22
Registered: 30-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 13-1-2009 at 14:23


Hi and happy new year. As you imagine theresn't news about RS232.

Today, I found whole TTY(??) with phosphor screen and keyboard and a voice whispered me again to try the SC602. The problem is the strange connector. For this reason I haven't taken it yet.
Connector seems to be a DB50 as three rows of pins. If it is I may find a cable and simply try. Yes, this may be less comfortable than excel and there's new risk of mismatched cable and broken screen, paper unavailable, rare cable, broken keyboard...
View user's profile View All Posts By User
densest
Hazard to Others
***




Posts: 359
Registered: 1-10-2005
Location: in the lehr
Member Is Offline

Mood: slowly warming to strain point

[*] posted on 16-1-2009 at 18:29


hmmm.... there is a term for reverse-engineering old computerized equipment: "necrocomputing" ;)

Older equipment with DB-25 pin connectors are often run at 1200, 2400, or 9600 baud.

Using antiparallel LEDs with 10K ohms in series, one can decode what the connector is intended to do.

There are a lot of RS232 references on the web, but they are often not very useful to a beginner.

Do you have access to an ohm-meter ? A combination voltmeter-ammeter-ohmmeter should cost less than (euros)20.

Pin 1 is "frame" or "protective" ground. It is connected to the chassis. It is usually NOT connected to any signalling device.

Pin 7 is "signal ground" and is the reference for all other voltages mentioned here.
Usually, pin 1 and pin 7 (if pin 1 is connected at all) are shorted together and an ohmmeter should read close to 0 ohms (less than 1) between them.

The interface is asymmetrical: it was designed to connect a user device (DTE, data terminal equipment) to a modem (DCE, data communications equipment), so all pins are connected to a transmitter on one end and a receiver on the other. You can tell which is which by using the voltmeter or the LEDs. Connect the reference point to pin 7, and measure the voltage or observe the LEDs.

Assuming that a voltage:

NEGATIVE more than 4 volts with respect to pin 7 is GREEN
POSITIVE more than 4 volts with respect to pin 7 is RED
less than 2 volts POSITIVE OR NEGATIVE with respect to pin 7 is DARK.

A pin with a transmitter will show either RED or GREEN.
A pin with a receiver will show about 1 volt positive or DARK.
A pin which is not connected will be DARK.

The computer DE-9 connector is defined to be DTE. It is very likely that the instrument is also wired as a DTE. In the spec, these are not allowed to connect to each other. In the real world, it is done all the time,so there is a well defined way to do that.

First, see if pin 2 or pin 3 on the 25 pin connector is connected to a transmitter. Whichever one is connected should show GREEN as the idle state of an RS-232 line. The other pin should be DARK.

The other useful pins are 4, 5, 6, 8, and 20.
Connect 4 to 5
Connect 6 to 8 to 20.

On the PC end, connect:
7 to 8
1 to 4 to 6

Connect the transmitting pin of 2 or 3 on the 25 pin connector to pin 2 on the PC
Connect the other pin (3 or 2) on the 25 pin connector to pin 3 on the PC
Connect pin 7 on the 25 pin connector to pin 5 on the PC

Once the machines are on (and in the PC case, a terminal program is connected), you should see:

pin 2 and 3 both are GREEN or flickering if data is being transmitted
all the groups of pins connected together should be RED

Now all you have to do is figure out what the data transmission rate is.

Note: searching the web seems to indicate that the company may have been bought by another company in Italy or Germany, so some telephone calls might get a manual or other information.

Good luck!
View user's profile View All Posts By User
hector_carbossa
Harmless
*




Posts: 22
Registered: 30-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 17-1-2009 at 17:03


Hi and thanks for your support. The problem is I have DB50 connector. I attempted similar tests with device's DB9, connecting resistor-2 antiparallel leds between pins and ATX's ground or +5. Approximately you can find results in this thread.

One hypothesis I thought is DB9 isn't real terminal connector but has to be connected with a keyboard-single line display system as in article on "Rejuvenating old computerized...".

TTY?(phosphor + keyboard/printer) I saw, seems to have a "bed of nails" form of DB50 (but I have now to check better).
All particulars induced me thinking this is real system asset (n.b. a bed of nails).

In instrument's inside all 50 pins are connected to something but in addition I don't know nature of that port nor pinout for these purposes. But working old terminal shall be more satisfactory than nothing and shall light on real port nature.

Manual you stated may exist as "oral tradition" content I may try getting from today's last users (if they remember to have a phone or e-mail).

I know approximately what are DB9 and coms ports so, I tried. Now I have just this trial before planning another use for my equipment.

Thank you again.
View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 17-1-2009 at 21:01


50 pin? Sounds like the old Centronics 50 pin SCSI connectors

http://www.nullmodem.com/Centronics.htm

http://pinouts.ru/HD/ScsiExternalCentronics50_pinout.shtml
View user's profile View All Posts By User
piracetam
Hazard to Self
**




Posts: 53
Registered: 20-5-2008
Location: 73X45
Member Is Offline

Mood: copacetic

[*] posted on 18-1-2009 at 20:00


*rubs hands*

this is a nice thread. I have one of these, with an LC Packings UZ-View (microbore) flow cell. I'd love to get this puppy to interface to my comp, I'm sure the workaround would be similar.

Attachment: AB785A.pdf (2.3MB)
This file has been downloaded 1726 times

View user's profile Visit user's homepage View All Posts By User
densest
Hazard to Others
***




Posts: 359
Registered: 1-10-2005
Location: in the lehr
Member Is Offline

Mood: slowly warming to strain point

[*] posted on 18-1-2009 at 22:24


Well, J7 and J8 are your I/O connectors - but it's set up as RS-423, a differential signal (nominally +5 and ground) between pairs (transmit +, transmit -) to (receive +, receive -). There are kits and assembled converters for this system, but your computer RS-232 style I/O won't talk to them very well directly. The big advantage of RS-423 is it can send data for long distances at high speeds in electrically noisy environments.

A key datum is the ICs used to connect to the outside world. Older equipment uses ICs with part numbers with 1488 and 1489 in them for RS232, more recent ones use MAX232 and similar ones. Seeing a 26LS32 or similar parts implies RS422 or 423 or 485. 75xxx parts are TI's variants - I -think- 75154 is RS232.

Conversely, if all you see are ICs with part numbers starting with 74 or 80 or 82, the connector is not capable of connecting to anything for more than a few feet at most, and the interface will be entirely proprietary (one exception is a 25-pin connector with a 74LS244 and 74LS374, which is a printer port). The 50-pin connector is very likely intended to go to a switch matrix and LCD/vacuum fluorescent display like the one shown in the PDF posted here.

Hope this helps - a list of ICs near the I/O connector in question would help.
View user's profile View All Posts By User
hector_carbossa
Harmless
*




Posts: 22
Registered: 30-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 20-1-2009 at 22:57


Hi and thank you.

All these things confirm me RS232 is for proprietary LCD/keyboard. AB's model seems to be quite similar to mine. For example, I've electronics on various extraible PCBs instead on one.
Thing to don't take light is absence of LCD/kb that may influence correct running, but at this point my purpose is trying the 50-pin hypothesis and at least, shorting RS's pins.

In RS trials my cable was about 50 cm. If possible I'll check IC's.

Naturally I've to see more accurately on AB'S manual and sparely, call some of those utilizators I stated.

At this time, main hypothesis is what I stated: 50-pins has to be connected to tube/keyboard/printer systems. Windows utilization is perhaps a chimera.

What toke me in trap was article on rejuvenation in which, 20mA loop (RS232's ancestor in my mind until now and now). In that article they have already I/O proprietary system and nonetheless, probably, a manual that resulted in correct port identification.

However, parallel port seems really to go to a printer. The problem is an eventual computer interfacing and nonetheless, a SCSI 1/ bed of 50 nails adaptor (thing I have to check as soon as possible) for TTY.
View user's profile View All Posts By User
hector_carbossa
Harmless
*




Posts: 22
Registered: 30-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 21-1-2009 at 21:28


Unfortunately, TTY's connectors are just a little different than a DB50. They have at least over 100 pins. So, utilization I proposed outcame from an hallucinatory state, theory time has to came and eons will be passed until a first utilization even if this will happen.

I only suppose using a SCSI controller may be new direction. But may be new gamble without a program.

As final thing, I remembered I have some images online. At this time, I post them just for completeness hoping this may be interesting or useful.





Ports (bad inquadration)



Inside. Far black box on left contains all electronics as extraible, self standing cards.

At this moment I am unable to check electronics details but I hope I'll can soon.

Good bye
View user's profile View All Posts By User
piracetam
Hazard to Self
**




Posts: 53
Registered: 20-5-2008
Location: 73X45
Member Is Offline

Mood: copacetic

[*] posted on 22-1-2009 at 12:54


Quote:
Originally posted by densest
Well, J7 and J8 are your I/O connectors - but it's set up as RS-423, a differential signal (nominally +5 and ground) between pairs (transmit +, transmit -) to (receive +, receive -). There are kits and assembled converters for this system, but your computer RS-232 style I/O won't talk to them very well directly. The big advantage of RS-423 is it can send data for long distances at high speeds in electrically noisy environments.

A key datum is the ICs used to connect to the outside world. Older equipment uses ICs with part numbers with 1488 and 1489 in them for RS232, more recent ones use MAX232 and similar ones. Seeing a 26LS32 or similar parts implies RS422 or 423 or 485. 75xxx parts are TI's variants - I -think- 75154 is RS232.

Conversely, if all you see are ICs with part numbers starting with 74 or 80 or 82, the connector is not capable of connecting to anything for more than a few feet at most, and the interface will be entirely proprietary (one exception is a 25-pin connector with a 74LS244 and 74LS374, which is a printer port). The 50-pin connector is very likely intended to go to a switch matrix and LCD/vacuum fluorescent display like the one shown in the PDF posted here.

Hope this helps - a list of ICs near the I/O connector in question would help.





pages 40-41 (section 1.16) reflect what you said, except that the protocols used are RS422 (rather that RS423) and RS232.
"U4 is a serial comm controller with two independent duplex channels. Channel A is used for the external serial communication. Channel B is connected to J1 (the power supply connector) for possible future use.
U34 is a dual differential line driver used for the transmit lines. Data from the U4 TXDA output is converted by U34 to two differential transmit lines, TXD+ and TXD. TXD+ can be used alone for RS232, the handshake line (HSK) is connected to the CTSA (clear-to-send) and TRXCA (transmit/receive clock) lines of U4."

hmm...it's all greek to me


[Edited on 22-1-2009 by piracetam]
View user's profile Visit user's homepage View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 22-1-2009 at 16:12


might look here

http://www.rs485.com/rs485spec.html

http://www.arcelect.com/rs422.htm
http://www.arcelect.com/RS423.htm
http://www.arcelect.com/rs232.htm

RS423 is sort of a enhanced RS232, faster data rate and longer cables can be used.

RS422 uses similar drivers and receivers as RS423, but differentially paired so the pair of transmit data lines are swinging +/- and -/+ for ones and zeros rather than a single line going positive and negative relative to ground. If the data lines are a twisted pair, then noise rejection is enhanced.

Both RS422 and RS423 have receiver and driver specs such that up to 10 receivers may be connected to the same data lines, listening to the same transmission. For full multidrop systems RS485 is used.

What they seem be be saying is that their driver/buffer chip is used to created the differential output signal, but if you use just the TXD+ signal you can pretend it is RS232 transmit data. This usually but not always works, some attention is needed to the different ranges of voltages and currents in RS232 and RS42X.

Note that while not at all common, these serial data signal types can be used in clocked mode, where the data clock is also transmitted over the cabling. Generally this is used with synchronous data, where there are no start and stop bits.
View user's profile View All Posts By User
piracetam
Hazard to Self
**




Posts: 53
Registered: 20-5-2008
Location: 73X45
Member Is Offline

Mood: copacetic

[*] posted on 22-1-2009 at 19:44


aw man..thanks.
this is somewhat reassuring. I have a 25ft. 9-pin cable (male to female)

perhaps all I need is some drivers to get it to work with LabVIEW?
i was thinking i need an DAC interface
View user's profile Visit user's homepage View All Posts By User
densest
Hazard to Others
***




Posts: 359
Registered: 1-10-2005
Location: in the lehr
Member Is Offline

Mood: slowly warming to strain point

[*] posted on 23-1-2009 at 14:59


It's an Appletalk port. 230Kb - no wonder you couldn't see it. There are commercial and homebuilt converters for that to a PC, or you could get a very old apple ;)

The funny mini-din (round with 8 pins) connector was the giveaway.

PLEASE for good help, post BIG CLEAR PICTURES! Without the picture it could have taken a long time to figure this one out!

And for the gentleman who started this thread - closeups of the CPU and I/O board and the wiring from the RS232 port to the boards might show something useful!


[Edited on 23-1-2009 by densest]
View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 24-1-2009 at 01:29


If it was doing Appletalk/lLocaltalk then it would likely have one of the Zilog SCC chips as the serial data interface (not the driver chips, but the big package connected to them). It a synchronous protocol based on HDLC, with a bit rate of 230.4 kbit/s, and ordinary UARTs aren't going to talk to it.

SFAIK the usual way to connect to a LocalTalk port using a newer Mac or a PC is to use a LocalTalk-to-Ethernet bridge or a software bridge running on a Mac that has both serial and Ethernet ports.

However:
Quote:
Spectrophotometer
The Spectracomp 602 double-beam microprocessor controlled instrument replaces the Model 601. Major features are a double optic with holographic blazed grating and an RS 232/C interface for external computing. It will be supplied with analytical programs for absorbance, transmittance and Concentration measurements.

sure implies that it's an ordinary RS232/RS422 port. Looking at the photo from above it appears that the mini-DIN and DB9 share at least some signal lines, perhaps it could operate in either mode?

[Edited on 24-1-2009 by not_important]
View user's profile View All Posts By User
hector_carbossa
Harmless
*




Posts: 22
Registered: 30-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 24-1-2009 at 03:06


I'm not sure I have found AB's manual defining ports usage in a manner that may be revelatory. As mine, your DB9 has small number of pins but may be intended for different utilization. On the other hand, manual seems quite clair on this. Have you ever done any sort of test?

Densest, unfortunately, in my old "album" there's not some representing each standalone extracted pcbs.

I'm pleasured deep interest come out and, as gentleman, I have to satisfy it. On the other hand, everyone interested, me included, shall wait just a little (while I find functional camera) to see more appropriated pictures on this thread.

In meantime, there's an introduction on SP602's inside world, hoping to calm down your knowledge thirstness and nonetheless, mine.



Cylinder on left, may be gas pump. On right, there's parallel(?!?) port hidding serial which has wired only upper pins. All wires converges in farthest, middle-left black box which contains pcbs. Nearest gray, black topped box contains opticals. On it's right, sample room and detectors. Always on right, rough power supply.


Splitted in two cards panel.



A thing to underline is setting focus on exact wires source perhaps may be difficult even if I "dismantle" instrument.

For all remaining things, I am not a field operator and I haven't new, good ideas. At this moment I'm not sure on my "small I/O" theory and when I look, at school, at greyish instruments wired to green phosphor, no one can say from where those setups come from.

A thing, I stupidly think about, is that in 80's may was another way to underline part missing. Missing deuterium lamp may feedback something on circuitry.


Quote:

However: Quota: Spectrophotometer The Spectracomp 602 double-beam microprocessor controlled instrument replaces the Model 601. Major features are a double optic with holographic blazed grating and an RS 232/C interface for external computing. It will be supplied with analytical programs for absorbance, transmittance and Concentration measurements. sure implies that it's an ordinary RS232/RS422 port. Looking at the photo from above it appears that the mini-DIN and DB9 share at least some signal lines, perhaps it could operate in either mode?


I read that review. In effects, the analytical program may be also a communication program. Upon now, problem remained: program is integrated in instrument or is supplied as 5 inches floppy disk? Perhaps only persistent users may answer to this question. Probably this will be categorically THE direction. Thanks.

[Modificato il 24-1-2009 da hector_carbossa]
View user's profile View All Posts By User
densest
Hazard to Others
***




Posts: 359
Registered: 1-10-2005
Location: in the lehr
Member Is Offline

Mood: slowly warming to strain point

[*] posted on 24-1-2009 at 09:10


It's possible that piracetam's machine can run in either mode, but the round connector is the one used for appletalk, the pins are connected as appletalk requires, the serial communications chip is a 82530 which Intel asserts is capable of handling "virtually any serial data transfer application", the usual handshaking signals are absent, the two connectors are daisy-chained for a bus architecture, and the pins on the DB-9 are not in the usual places for a RS-232 connection. IF the machine is capable of being run in an RS-232 mode it would need a special cable: one that carries data from the instrument on pin 4, to the instrument on pin 8, signal ground on 1 or 3, and needs pin 7 grounded (short 7 to 1 or 3).

I think Mr. Carbossa's machine is using something approximating regular RS-232 connection - a session with a voltmeter might confirm this.
View user's profile View All Posts By User
 Pages:  1  2

  Go To Top