6ES7531-7KF00-0AB0 S7-1500 8-Channel Input No Supply Voltage at L+ Error

Dear All

I am currently trying to configure my S7-1500 CPU to read a 4-20mA value at channel 1 Analog Input Card Module (6ES7531-7KF00-0AB0) 4 wire transducer type to read a 4-20mA and display it on a scada screen.

My network are as follow

S7-1500 CPU+PS 24VDC connect with Distributed IO ET200MP Interface Module Profinet via Switch network hub. The ET200MP also has various module connected to it such as 6ES7531-7KF00-0AB0 8AI Card and a 8DI & 8DQ card.

My Problem face are as follow

TIA Portal analog input show a constant 32767 (prior NORM_X and SCALE_X) regardless if there is an 4-20mA value injected into channel 1 or not. Apparently I am facing issue with "Supply Voltage Missing" at Channel 1 which according to diagnostic show "No Supply Voltage at L+" (the LED indicator of channel 1 will blink red)

Attachment show 3 picture, the first picture shows the connection of an 4-20mA injector inject into channel 1. The 2nd picture shows the measured 24VDC from point L+(41,42) M(43 & 44) thus providing necessary power to analog module.

Has any one face the issue where either one of AI channel has a "No Supply Voltage at L+" error even though there L+ and M are connected (shown in picture number 2 with multimeter) if so what are your remedy on how to resolve TIA not able read the analog input channel

Thanks in Advance

Foo Brandon

Hello BrandonFoo,

It is indicating a power failure on channel 0.

I recommend that you disable the channels you are not using.

JBS98

Hello BrandonFoo,

It is indicating a power failure on channel 0.

I recommend that you disable the channels you are not using.

 Dear JBS98

Thanks for the prompt reply

Can you please elaborate more on the power failure on Channel 0.

I have did a prior test on using similar circuit connection and it work out perfectly. But this time i encounter this problem. In my prior test i did not enable this Diagnostic error "No Supply Voltage L+ setting", this time i enable it the diagnostic error i encounter this error.

sincerely

Foo Brandon

BrandonFoo

Dear JBS98

Thanks for the prompt reply

Can you please elaborate more on the power failure on Channel 0.

I have did a prior test on using similar circuit connection and it work out perfectly. But this time i encounter this problem. In my prior test i did not enable this Diagnostic error "No Supply Voltage L+ setting", this time i enable it the diagnostic error i encounter this error.

sincerely

Foo Brandon

Okay, I understand.

Your sensor is a 2-wire intensity sensor, right? If so for channel 1 must be connected the + to pin 5 and the - to pin 6 as indicated in the manual, do you have it that way (I can't see the pins very well in the document sent, sorry)?

SIMATIC S7-1500/ET 200MP Analog input module AI 8xU/I/RTD/TC ST. Wiring

JBS98

 

BrandonFoo

Dear JBS98

Thanks for the prompt reply

Can you please elaborate more on the power failure on Channel 0.

I have did a prior test on using similar circuit connection and it work out perfectly. But this time i encounter this problem. In my prior test i did not enable this Diagnostic error "No Supply Voltage L+ setting", this time i enable it the diagnostic error i encounter this error.

sincerely

Foo Brandon

 

Okay, I understand.

Your sensor is a 2-wire intensity sensor, right? If so for channel 1 must be connected the + to pin 5 and the - to pin 6 as indicated in the manual, do you have it that way (I can't see the pins very well in the document sent, sorry)?

Dear JBS98

Initially I did inject a 4-20mA using 2 wire however with the 2 wire connection i did not managed make it work. Then I transition to 4 wire connection plus the L+ and M connection and the connection work perfectedly.

This time I inject a 4-20mA using and injector with a 4-wire connection and the TIA portal show 32767 constant value.

Have you encounter the value 32767 being show in TIA portal before? I mapped the input correctly and the input does not reflect the 4-20mA which has  range of 0-27648. 

sincerely

Foo Brandon

BrandonFoo

 Dear JBS98

Initially I did inject a 4-20mA using 2 wire however with the 2 wire connection i did not managed make it work. Then I transition to 4 wire connection plus the L+ and M connection and the connection work perfectedly.

This time I inject a 4-20mA using and injector with a 4-wire connection and the TIA portal show 32767 constant value.

Have you encounter the value 32767 being show in TIA portal before? I mapped the input correctly and the input does not reflect the 4-20mA which has  range of 0-27648. 

sincerely

Foo Brandon

Hello again BrandonFoo,

Ok, so now you have the channel configured as 4-wire.

Are you connecting the + wire from the sensor to pin 5 and the - pin from the sensor to pin 7 and then powering the sensor correctly with 24V or whatever voltage it needs?

This is the final output shown in red box the value is showing a constant of 16#7FFF or 32767 value in decimal

Please reply as soon as possible

sincerely 

Foo Brandon

Yes, I understand that.

When the value show in TIA Portal is 32767 means that there is an overflow. So the first step is to review the wiring for in case there is a problem there because the most of the problems comes of that.

So the wiring is like I told you in previous post?