how to send 1 analog signal to 2 PLC

[minhdam06102 0]

Dear Mr/Ms, I have an ultrasonic sensor with 4-20mA analog signal output. But I have 2 control panel with 2 PLC separate, two PLC have analog input module . Can I send signal for 2 analog module of 2 PLC with one sensor? If can how can I make them - Analog signal will connect analog (+) and analog (-)with module analog of 1st PLC and then from that terminal (analog terminal of 1st PLC) wiring to analog (+) and analog (-) of 2nd PLC ? or - Analog signal from sensor (+) will connect with (+) analog 1st PLC then (-) analog of 1st PLC will connect with (+) of 2nd PLC then (-) 2nd PLC will connect with (-) sensor ? or - Analog signal from sensor (+) will connect with (-) analog 1st PLC then (+) analog of 1st PLC will connect with (-) of 2nd PLC then (+) 2nd PLC will connect with (-) sensor ? Would you please help me to solve this? Thanks & best regards,

[Bering C Sparky 7]

This looks like it would be the correct way to put multiple analog devices in series. - Analog signal from sensor (+) will connect with (+) analog 1st PLC then (-) analog of 1st PLC will connect with (+) of 2nd PLC then (-) 2nd PLC will connect with (-) sensor ? However I am in no way telling you to do this between 2 PLC Analog inputs in seperate PLC's. Maybe it would be fine, but then again MAYBE NOT. Hopefully others more experienced will chime in to advise you. I am sure there are many factors that need to be addressed before attempting this. We have no idea what PLC's, AI cards or type of sensor you are using. In my opinion your best and safest bet would be to use something like this: https://www.phoenixcontact.com/online/portal/us?uri=pxc-oc-itemdetail:pid=2814867&library=usen&tab=1#Outputdata This signal multiplier will give you isolation between the sensor and the two plc's. Regards, BCS

[b_carlton 61]

Please specify the exact model of PLC and analog input. This may or may not be possible but too little information is given.

[mikey431 3]

You need more details to figure that out. What is the sensor manufacturer recommendation for wiring this signal to a PLC ? One you know that, you can wire the signal in series to send signal to both PLCs. However, there are other involving factors including if the sensor is sink or source power instrument? do both PLCs have same ground or 0 V ? how far is the distant between the PLCs? ..etc. The best way is using a signal splitter (conditioner) device to isolate the output signals. Edited 3 Jul 2014 by mikey431

[bartolim 0]

I agree with Mikey... depending on the device and PLC I/O card configuration, you may or may not get a workable solution by just making a series connection. In addition, one loose connection and you lose both PLC inputs. A better solution is to use a signal conditioner as he describes to split one current loop into two; one that we use a lot is the Phoenix Contact MCR Signal Multiplier: https://www.phoenixcontact.com/online/portal/us?uri=pxc-oc-itemdetail:pid=2814854&library=usen&pcck=P-13-15-03-01&tab=1

[ASForrest 12]

A better option would be to just put it into one PLC and then send the information from that PLC to the other over ethernet. What sort of PLC's are they?