Hi.
I have a Cole Parmer pump, which accepts serial commands over DB-9 RS-232 (Manual attached as "ColePalmer-MasterFlex LS 7551-00 P3.pdf"). I have connected it to a laptop via a USB/Serial adaptor and I'm trying to send commands to it via MAX>>VISA Test Panel, or any other text interface for that matter. I can't communicate with it, except for one command.
Here's what I know/have done:
1- The manual specifies all the connection specifics: baud rate=4800 bps, 7 data bits, 1 stop bit, "one odd parity". "The serial data format is full duplex"
2- The manual provides a detailed description of a start up sequence.
3 - "Normal start up would consist of turning on all the satellite units first and then the control computer". This is not what I do (I don't want to restart my computer everytime I want to restart my work!) . I turn the pump on (keep it on), and then connect the RS-232 cable.
3 - "Each satellite will enable its receive and transmit buffers and activate its RTS line. The control computer would then send the enquire <ENQ> command in response to the active RTS line". Here satellite means a pump. I can send the <ENQ> command (ASCII 05, or CTRL+E in a text interface), and I receive "\x02P?0\r", which is the expected response. I do this in the VISA Test panel by writing "\05" to the port and reading the result. "\x02" is the "start of text" <STX> character and the response shows the kind of satellite at hand (here it's a 600 rpm pump).
4 - "The control computer would then send back <STX> Pnn<CR> with nn being a number starting with 01 for the first satellite and incrementing for each satellite up to 25 maximum". This is where it fails: I try sending "\02P01\r" in VISA Test panel and I don't get anything (well, I get "0xBFFF0015" Timeout expired before operation completed).
5 - The pump is supposed to perform other tasks after this point and take certain actions, but since I don't get there, I didn't report it (it's outlined in the attached manual).
I have had the same results either with the VISA Test panel, or using the "Basic Serial Write and Read.vi" provided with LabView (attached file Basic Serial Write and Read.vi). I have also attached a serial session capture of the above sequence (more or less) as 0406 capture.txt. I tried reading only 50 bytes to avoid a Timeout using the default 1024 read length. I have also tried the flow control options NONE and CTS/RTS, with no positive results.
The manual states that "Before a pump drive can be controlled, it must first be numbered. If any command is issued before this is done, the satellite will not respond.". So I guess that's why I had no luck with any of the other commands (like the one in the captured comm session).
The USB/Serial cable was a UPnP cable, but I installed its drivers, too. I take that the initial communication with the pump verifies that (1) the cable is ok (2) the port and the pump can hear each other. I have already contacted the manufacturer and waiting for their response. They don't have any LabView drivers (as far as ni.com can tell me). The pump is already set to remote mode.
It should be pretty obvious from above that I have zero LabView (or instrumentation and seril communications) experience and this was supposed to be my "intro to LabView"! I already searched the forums but it seems ost issues are realted to COM port recognition, cable problems or device-specific.
I would highly appreciate any feedback/tips/links to further reading, etc.
Cheers
Ali