Author Topic: Input from other Plc output  (Read 14308 times)

can

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Input from other Plc output
« on: June 28, 2015, 06:04:43 AM »
Hi. Can the input of fmd88 be connected to the output of another Plc sharing the same power supply? If I connect both together and everything works as normal, does it mean that it should work? Thank you.

garysdickinson

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Re:Input from other Plc output
« Reply #1 on: June 28, 2015, 07:13:35 AM »
Yes.  I interconnect TRI PLCs using INPUTs driven by OUTPUTSs for many reasons.

The specs for the INPUTs and the OUTPUTs on most of the TRI PLC are such that the can be interconnected. The use of a single power supply for both PLCs simplifies the problem.

Gary d


can

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Re:Input from other Plc output
« Reply #2 on: June 28, 2015, 08:12:29 PM »
Hi Gary. Thanks for the advice. Do you know if I can hook up anything to FMD88 to detect the line current? Need to detect maximum 1 amp dc current in a wire. If the line current falls below 1 amp, I'll get the PLC to send a notification.

jonathan.kaye

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Re:Input from other Plc output
« Reply #3 on: June 29, 2015, 07:07:35 AM »
http://www.automationdirect.com search DCS100-AE-24-F

90$ USD but free shipping to Canada. Check the specs though! (line diameter, max current)

Looks like it has a solid state relay in it for the signal, I really don't know if it will work with the FMD's input (ground signal).
« Last Edit: June 29, 2015, 07:09:12 AM by jonathan.kaye »

garysdickinson

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Re:Input from other Plc output
« Reply #4 on: June 29, 2015, 12:36:01 PM »
I second, Jonathan's recommendation.

The device he suggested is a current switch and it can be connected to a PLC input.  The output of the DCS will close (go active) when the DC current is greater than the set point.

Please note that the minimum current that the DCS100 can detect is 5A DC.  You want to sense 1A DC.  You will need to loop the wire that you are trying to sense several through the "eye" of the current sensor several times so that when 1 A is flowing through the wire, the sensor will think that 5 or more A is flowing.

Automation Direct also offers the DCT100 current transducer that can work with the FDM88 analog inputs.  If you need to measure current and not just have a on/off indication, then a current is what you want.

Gary D.
« Last Edit: June 29, 2015, 12:37:31 PM by garysdickinson »