Tenma power supply: using the serial port

[Mike1]

I have recently bought a Tenma 72-2635 triple-output power supply from Element14.  It works correctly when I use the front-panel knobs, but I cannot get any response to commands that I send into the RS232 port.  The instructions are very sketchy, and I don't know whether there is an actual fault in the supply, or whether I am doing something wrong in sending the commands.  For example, the manual claims that sending "OUT1" (without the quotes) should turn ON the output.  I start up Microsoft's Hyper Terminal (Windows XP),  set the baud, stop bits etc as specified,  then type OUT1, and nothing happens.  If I unplug my serial cable from the power supply and terminate it withy a loop-back plug (pin2 connected to pin 3 on a DB9 plug), then OUT1 is reflected to the screen, as it should be -- so the command is atleast getting to the power supply.  In case my typing is too slow, I tried putting OUT1 in a .txt file, then sending the file.  I was able to send that by selecting Kermit protocol and "send as text file".  But the power supply ignored it.
I have also tried replacing Hyper Terminal with the MTTTY communicartions programme, without success.
Am I doing something wrong, or is it the supply?

[halexa]

Hi I have a 1 port Tenma power supply that i got working over serial with Python.
Don't know if the protocol is same but could be worth a try

Code:
ser = serial.Serial('COMxx')             #depending on used serial port
ser.write(b'VSET1:12.00')      # set voltage to 12V
ser.close()

[Mike1]

Thanks, Halexa.  I prefer not to use python if I can help it, but I will keep your comments in mind.  The 'VSET1:12.00' is the same protocol as mine. 

[cowana]

Have you tried sending a carriage return and line feed (CRLF) after the command?

[Andreas]

Am I doing something wrong, or is it the supply?

Your typing speed is too slow so you run into a time out.

I copy the commands with "CTRL-C" and "CTRL-V" from a text file into the terminal program.
(using a KORAD KA3005P which is a unbranded version of the TENMA)

with best regards

Andreas

[Mike1]

Thank you all for your help, and my apologies for this late response.  I eventually sat down, learnt some Python and bought a USB to RS232 dongle.  Initially nothing worked, then I found that inserting a 0.1 second pause  ( time.sleep(0.1) ) between commands solved the problem. Now it works well.