SM 331 (AI 8 X 12 bit) configure.

Dear all,

I would like to ask the question about the SM 331 (AI 8 X 12 bit) configure.

1. Can the AI module configure different type of sensor?

For example:

Channel 0-1  0-10V
Channel 2-3  4-20mA (2-wires)
Channel 4-5  0-10V
Channel 6-7  0-10V

2. However, as I know that the type of 0-10V of the -ve wires is requested to connect with the Comp+ and Mana together for the ext. compensation.

In my case, when the channel 0-1 is connected to the flied equipment, the value of the channel 2-3 will be reached to the max value of my setting. It's a abnormal condition.

Should the channel of the 2-3 do the same with channel 0-1 in the wiring for compensation? But, If I do that, can I receive the value of 4-20mA (2-wires)? Because only 4-wires is requested to wire with the compensation.

P.S The Step 7 hardware configure and AI module hardware channel block is both correct.

hi Allen,

1. yes you can. You can parametrize each channel-group for its own. you also have an own measure range module for each channel-group. 

2. you don´t need the ext. compensation by 2-wire transducers, like you can see in the manual, chapter 6.7.

Be sure that you really have a 2-wire-transducer. If it has an external power supply, you probably have a 4-wire-transducer. Therefore you should use the external compensation. Be sure that the compensation i grounded(functional ground). 

hope this helps,

regards,

mopS04

hi Allen,

1. yes you can. You can parametrize each channel-group for its own. you also have an own measure range module for each channel-group. 

2. you don´t need the ext. compensation by 2-wire transducers, like you can see in the manual, chapter 6.7.

Be sure that you really have a 2-wire-transducer. If it has an external power supply, you probably have a 4-wire-transducer. Therefore you should use the external compensation. Be sure that the compensation i grounded(functional ground). 

hope this helps,

regards,

Hi mopS04.

Thank you for your answer. Attached is my AI module wiring diagram. Is it right?

Yes. The channel of 2-3 is 2-wire transducer type. However, I don't know why it was reached to the max value (100, setting:0-100) when I connected the sensor of the channel 0. 

New question published by neO0O is split to a separate thread with the subject S7-300 redundant signal.

Best regards
Jen_Moderator