Hi,
We are working with AB-CompactLogix L32E controller including Compact I/O 1769-IF8 analog input module. We have been configure 1769-IF8 module as engineering units (Min 4000 to Max 20000).

At the analog input side we have connected Non-Loop powered 4-20mA Amplifier as per 1769-IF8 wiring drawing (Iout+ to Iin+ and Iout- to V/I in-). The amplifier successfully generate the 4-20mA signal without oscillation at the output terminal. But the controller shows only 3200 (engineering unit) value with no change.

We don't know what's the problem is. Also we had double check our input wiring connection and module configuration there is nothing wrong. Apart from that please give us solution to eradicate this problem and give any suggestion.

 

Are you sure the input is configured to read a 4-20mA current signal?

 

Hi,
...Also we had double check our input wiring connection and module configuration there is nothing wrong. Apart from that please give us solution ....

If we are not supposed to check the configuration and wiring, there are only few ways forward:
1. replace module and try again
2. hire someone
3. lets check the configuration and wiring.

 

Iout+ to Iin+

so far so good...

Iout- to V/I in-

and that's it? that is wrong....

 

Hello,

Is this the installation manual for the I/O module?

In there you will find a variation of input connections.

Bertus

 

I have a problem for getting the 4-20mA input via 1769-IF8 I/O module. My field device is good condition, but my AI card doesn't respond. when i have to browsing about it. most of them said, the impedance of the field device and AI module is not matched.
I don't have any idea about to matching the impedance of both, so explain me about how should matching the impedance successfully.

 

that makes no sense. impedance matching is used with transmission line to prevent or reduce standing waves. that has nothing to do with slow changing DC signal. so, are we going to guess what you have there or you will consider sharing what and how you have connected and what settings did you use? your choice...

 

for any circuit, including 4-20mA current loop of your sensor, there must be a closed path involving power source, sensor and input card. if your input card is reading open circuit, your wiring or configuration are not correct. since this particular card is very flexible - there is plenty of ways to us it.

if you want help, you need to post details such as your sensor model (preferably with link to datasheet), connection you are trying to use and configuration details of your card.

you can measure current from sensor to PLC input and compare measurement with PLC reading.

 

Are you sure the input is configured to read a 4-20mA current signal?

yeah, I'm sure input is configured to 4-20mA current signal.

 

Hello,

Is this the installation manual for the I/O module?

In there you will find a variation of input connections.

Bertus[/Q

yes, thank you bertus

 

for any circuit, including 4-20mA current loop of your sensor, there must be a closed path involving power source, sensor and input card. if your input card is reading open circuit, your wiring or configuration are not correct. since this particular card is very flexible - there is plenty of ways to us it.

if you want help, you need to post details such as your sensor model (preferably with link to datasheet), connection you are trying to use and configuration details of your card.

you can measure current from sensor to PLC input and compare measurement with PLC reading.

please find the our referenced attached documents for wiring connection and engineering unit for 4-20mA.

 

that makes absolutely no sense...

you are showing that you use connection for sensor with differential VOLTAGE output, but expect to read CURRENT input.

clearly you don't understand the difference, and this is why you are reluctant to share what exactly you have done, what exact model of the sensor you have, how exactly YOU have wired it (not the datasheet connections), why don't you use multimeter to VERIFY if the PLC reading matches reality (and reality is that PLC reading is correct - there is no current at that input which is what PLC is showing you), etc.

if you need help, be ready to share the situation. we cannot help you by guessing.

 

Please I need a help in constructing a circuit for controlling an industrial Synchronous motor with dual power source.

 

that makes absolutely no sense...

you are showing that you use connection for sensor with differential VOLTAGE output, but expect to read CURRENT input.

clearly you don't understand the difference, and this is why you are reluctant to share what exactly you have done, what exact model of the sensor you have, how exactly YOU have wired it (not the datasheet connections), why don't you use multimeter to VERIFY if the PLC reading matches reality (and reality is that PLC reading is correct - there is no current at that input which is what PLC is showing you), etc.

if you need help, be ready to share the situation. we cannot help you by guessing.

Sorry, I mentioned in the wiring diagram is wrong. Actually that below one (Differential current transmitter) from where that arrow indicates.
Actually that sensor is our own make now it is under testing stage, so i do not have rights to reveal it. And we had already verify the reading by using Multimeter. it shows the reading correctly.

 

1. still pointing to datasheet rather than showing YOUR wiring
2. still not showing HOW did you verify that current really goes (or doesn't) into PLC input. you only stated that you tested sensor output. that is fine but you did not confirm that measurement was done with current going into PLC input.
3. still not showing YOUR settings in PLC.

i am loosing patience trying to help someone that does not communicate. Zero feedback on very specific set of questions. To me this means your posts are no different than spam. good luck, i'm out...