control the flow rate of a Merck-Hitachi L-6200A HPLC pump

[dubbehendrik]

Hello,

I am trying to control the flow rate of a Merck-Hitachi L-6200A HPLC pump. I already found a VI in this forum in the post listed below:

http://forums.ni.com/t5/LabVIEW/HPLC-pump-feedback-control/td-p/1612428

I set the pump switches according to the manual as well as I have switched the pump to remote mode. Also I adjusted the settings of my COM port in the windows system manager according to pump and LabView settings. The problem is, that the pump won't react do any signal sent from the computer. I used "free serial port monitor" to ensure that a string is sent througt the COM port. Does anyone have any idea what might be the problem here? I'd really appreciate some help. Thank you all in advance,

Greetings,

Hendrik

[nyc_(is_out_of_here)]

Have you taken LabVIEW out of the picture by using something like Hyperterminal to communicate to your deivce and made sure you have the right type of serial cable?

[dubbehendrik · Accepted solution]

Hey,

thank you for the answer. This was indeed the hint in the right direction. I used RealTerm to try to send a signal to the pump. The problem was apparently the type of string I sent to the pump. In the abovementioned discussion the space string was sent as "\s" but apparently it can directly be sent as " ". Yeah, it's always the little details... Thank you anyway for your help.

Greetings,

Hendrik

[nyc_(is_out_of_here)]

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dubbehendrik wrote:The problem was apparently the type of string I sent to the pump. In the abovementioned discussion the space string was sent as "\s" but apparently it can directly be sent as " ".

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Hi,

It is not the type of string, but how the string is displayed.  \s  and the space character " " are the same thing.  It is mentioned in the response by johnsold in the link you had in your first post. http://forums.ni.com/t5/LabVIEW/HPLC-pump-feedback-control/td-p/1612428

[dubbehendrik]

I'm really not a total Labview pro ;-). Sorry for the sloppy formulation.