Keithley 2231A-30-3 Communication

[simba15]

Hi there,

I am working with a large number of the Keithley 2231A-30-3.

I would like to communicate with it VIA PC but Tek, states you must use the Keithley USB adapter ($$$)

I have found the pin-out of the propriety connector (2=rx,3=tX).

Has any one been able to get this power supply to communicate to their pc? ( may only respond to read only commands)

Thanks.

[simba15]

So I connected a FTDI TTL adapter tx/rx and tried with EEZ studio to get a response for a *IDN? command.

I cant get a response in the software but i can see that both Tx/Rx lights illuminate. (there is a response of some kind.)

Any ideas where the issue could be?

I will try with "Test controller" software.

[alm]

Did you try different baud rates / flow control / parity / stop bit configurations? If it outputs anything on power on, you could capture that with a scope or logic analyzer and check the repetition rate and count the number of bits.

[simba15]

Did you try different baud rates / flow control / parity / stop bit configurations? If it outputs anything on power on, you could capture that with a scope or logic analyzer and check the repetition rate and count the number of bits.

So the Manual Lists the Baud rate and flow settings 9600,8,N,1 ( this is what the program is set for)

If i use a incorrect baud rate 57600 or other, the RX light dose not illuminate.

I will try and scope the RX Line.

[BennoG]

was you been able to communicate with the device ?
It uses 3.3V level RS232 signals at 9600 baud.

I found it to be very slow for the measurements of the output Voltage and Current (300+ ms per query)
Have you come around this problem ?

Benno

[simba15]

interesting!

I probably fried it with standard RS232 levels as it stopped responding at some point. ( duh... it says (TTL) lol)

I have 10 or so of them so I may try again with 3.3v levels.

Thanks.

[BennoG]

Be also aware that the RS232 output uses the same ground level as CH3 output.
So I put also a isolator in the USB-RS232 converter (there is 5V on the 9 pin sub-D to supply the psu part of the logic)

P.S. I figured a way around the slow communication, see my other post in  on the 2231A, including C# source code and a nice HMI you can use to click on.

Benno

[Smokey]

wow.  I was just looking at one of these supplies online.  what a crazy decision to include a DSub and force your users to buy a $97USD USB adapter.  Seriously what the hell were they thinking? 
This design doesn't much look like other Keithley stuff, so I'm guessing it's a rebadge or something.  But still. 

https://www.mouser.com/ProductDetail/Keithley-Instruments-Inc/2231A-001?qs=DWa7j9kREiEoYVPT6mrqPg%3D%3D

https://www.mouser.com/datasheet/2/403/077101500_USBadapter_8-3358684.pdf


https://download.tek.com/datasheet/2231A-30-3_Datasheet_1KW-61078-0.pdf

Control the Supply and Upload Data to a PC
Use the optional Model 2231A-001 USB Adapter to control the Model 2231A-30-1 via a PC’s USB interface, then transfer readings from the outputs to combine with other test data for a more thorough analysis of DUT performance. The 2231A-001 USB Adapter provides the flexibility to use the supply under either manual or automated control.

So it's not like they expect you to directly use the DSub, and the USB cable is optional or something. 

[chilternview]

I guess a bean counter objected to having a MAX232 in there to convert to proper RS232 levels, "oh it will cost $1"...

Still rather than pay for the adapter you could make one with said chip and a little effort. The 2231A is a good power supply, I use mine all the time.

[BennoG]

Too bad the communication can nog go above 38400 baud. But I use it also al the time with a home made isolated TTL232 to USB converter.

So the 5V output is also isolated from the ground of the PC.

Benno

[htrueba]

I managed to get communication working without their connector. All I had to do was get an FTDI TTL converter (https://www.amazon.com/NITOMTYU-Serial-Adapter-TTL-232R-RPI-Windows/dp/B0CFV96CDD/)  and a DB9 breakout connector (https://www.amazon.com/Breakout-Connector-RS232-Serial-Terminal/dp/B073RGFD3Q/).

The links were just to example items but I'm sure they can be found for cheaper somewhere else.

Just connect RX, TX, and GND on the ttl cable to TX, RX, and GND on the DB9 breakout board . If it doesn't work immediately, swap RX and TX.

Hope this helps someone else!