RS 33 CHILLER

[darnell]

HI GUYS . BASICALLY IM TRYING TO COMMUNICATE WITH THIS RS 33 CHILLER FROM FTS. IM USING THE SERIAL COMMUNICATION. WE ARE USING RS 232 ENET CONVERTER . FROM THE CONVERTER WE ARE TO ACCESS FOUR MORE PORTS. WITHIN THE FOUR PORTS WE ARE USING AN RS 232 INTERFACE CABLE TO THE RS 33 CHILLER.

NOW THE  THINGS I HAVE TRIED SO FAR .

FIRST I MADE SURE MY LOOP BACK TEST WORKS, BY CONNECTING PINS TWO AND THREE ALSO SEVEN AND SIX ON THE END OF THE SERIAL CABLE. THE LOOP BACK TEST WORKS FIND.

BUT AS SOON AS I CONNECT THE RS 232 CABLE TO THE INSTRUMENT NOTHING HAPPENS. I USE THE HYPER TERMINAL ON THE COMPUTER TO TEST THE INSTRUMENT. IT WONT LET ME SEND NOTHING OUT. I ALSO THE MAX, WHICH IS THE MEASUREMENT AUTOMATION AND EXPLORER,I TRIED THE  SERIAL AND  COMMAND PROJECT THATS IN LABWINDOWS AND NOTHING HAPPENS. 

I HAVE ALL MY SETTINGS CORRECT AND WHAT COMPORT IM TALKING TO.  BAUD AT 9600, STOT BITS 1, PARITY  NONE, DATA BITS 8, FLOW CONTROL NONE. 

SO I REALLY DONT KNOW WHATS THE ISSUE. 

SO IF I CANT GET IT TO SPEAK TO THE INSTRUMENT THROUGH HYPER TERMINAL, I KNOW I CANT USE A THIRD PARTY CODE.

SO CAN SOMEONE ASSIST ME , IM GOING TO ATTACH  THE MANUAL AND THE WIRED DIAGRAM. 

ALSO WE TRIED NEW CABLES AND ALSO WE WIRE THE CABLE ACCORDING TO THE DIAGRAM.

[Henrik_Volkers]

As noted in the manual, you only need three wires GND(5) and TX,RX (2,3) , often pin 2 and 3 mix up, so it's a good idea to swap them and give a try.

In hyperterm (or with LabVIEW example 'simple serial write and read.vi' ((remember to send a termination character !!)) choose flow control NONE.

Another problem could be the sometimes reduced voltage levels on modern RS232 ports. A scope or simple handheld multimeter can give you an answer. Voltage levels >+-10V (?)should be fine. Since it is explicit noted in the manual, the chiller might be sensitive to lower levels. The 10V are my personal guess.

[AnalogKid2DigitalMan]

If possible, try a direct connection between an RS-232 port on the PC to the chiller first and eliminate the Enet converter as a possible source of problems.

-AK2DM