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Send current/voltage signal via DB25/USB to control Pump

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Hi All!

 

I want to control the speed of a pump with LabVIEW (Thermo Fischer FH100M, manual) and therefore I have to send either a current or a voltage signal to the pump. The pump only has a DB25 port. As my laptop doesn't have a DB25 port I tried to control it with a USB converter.

I only had a USB to DB9 converter, so I started with USB(laptop)->DB9->DB25(pump).

When I connect the pump to the USB port, it instantly starts to move, but in a strange way.

Is it possible to use this configuration? Or is it possible to use at least USB->DB25 (I have the pin configuration, see manual page 45/3-19)? Then I would order that cable.

Or do you have any other suggestions?

 

Thanks so much in advance!

 

Tobi

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Accepted by topic author PTobias

Tobi,

 

STOP! Do not connect your converter to that device.

 

When you say "USB to DB9 converter" are you referring to a USB to RS-232 converter? DB9 is just a connector and so is DB25. Tou can wire anything you want to such a connector.  Your converter most likely is wired like a RS-232 serial port.

 

The manual clearly shows on page 3-19 and the following pages that the pump control is NOT wired for RS-232!  From looking at the speicifications for the inputs and outputs shown on page 3-20 and 21 you could damage either the USB to RS-232 conveter or the pump controller by connecting them. 

 

To control this device you will need a DAQ device with Analog Inputs, an Analog Output, Digital Inputs, Digital Outputs, a Counter. You will also need some external circuitry such as transistors or DC-rated solod state relays.

 

Lynn

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Thanks for your help, I will try to get a DAQ device.

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How can I know if a pump control is wired for RS-232?

I have a new pump here and I wanna know if I could connect it to a Laptop with LabVIEW.

You can find the manual here (page 35 or 3-21): http://www.coleparmer.com/Assets/manual_pdfs/07525-20-40MF-IM.pdf

 

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@PTobias wrote:

How can I know if a pump control is wired for RS-232?

I have a new pump here and I wanna know if I could connect it to a Laptop with LabVIEW.

You can find the manual here (page 35 or 3-21): http://www.coleparmer.com/Assets/manual_pdfs/07525-20-40MF-IM.pdf

 


RTFM, that's how.

 

Also when spec'ing a pump look for one that specifies it is controllable through a serial (RS-232) or USB port

========================
=== Engineer Ambiguously ===
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Surely you can see that your new pump has EXACTLY the same specifications concerning its control connections.  Both manuals have obviously copied the same spec page so I'll bet that pinout is some industry standard.  No USB or serial comm on that one either.

 

If you need a pump with USB just Google:  Peristaltic pump with USB 

LabVIEW Pro Dev & Measurement Studio Pro (VS Pro) 2019 - Unfortunately now moving back to C#, .NET, Python due to forced change to subscription model by NI. 8^{
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Okay thanks, I did not order the pump, it's just available to me now.

So if I cannot read anything about RS-232, I can always assume, that it's not supported?

I already know some pumps with USB, but currently I am not going to buy one of them.

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Yes, you have to check the specifications page and look for the communication or interface options.  Many products have multiple interfaces built in, and some have them as options you can add for an additional cost.  

 

Also, ideally, if you have an option for USB, GPIB, Modbus, RS-232 (or WHATEVER), check to see if the company offers LabVIEW drivers as well.  That will make working with it very easy.  If you use RS-232 for instance, and DON'T have LabVIEW drivers, it will be up to you to read the ASCII strings coming from your pump through the RS-232 COM port and interpret the data.  How easy that is depends on the way the pump manufacturer's designed their product.  Sometimes they use simple string commands you can understand easily and sometimes it's a confusing mess of HEX based registers that can be confusing if you don't know the product very well.  Do some research and talk to the company engineering reps before you spend a lot of money on a pump that will be frustrating to talk to.  Smiley Wink

LabVIEW Pro Dev & Measurement Studio Pro (VS Pro) 2019 - Unfortunately now moving back to C#, .NET, Python due to forced change to subscription model by NI. 8^{
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Which pins would I connect to what pins on an pcie6323 nidaq to be able to control a pump. I created my own cable which has the pins isolated from the 25 pin cable. Which pins from this cable should I now connect to the nidaq in order to be able to control the pump? The pump I am using is https://www.masterflex.com/i/masterflex-l-s-digital-drive-600-rpm-115-230-vac/0752220

 

Any help would be greatly appreciated

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Hi sman,

 

you need atleast the voltage speed input, the remote start/stop and the CW/CCW inputs... (All with their respective ground pins.)

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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