Analog input module

Hello,

I have a sm 331 analog Siemens module and i'm having trouble wiring it up.

The manual tells me to wire it like "picture 1".

But i thought it had to be like "picture 2".

A few facts :

- Siemens S7 331 7KF02 0AB0 module
- I want to have a 4-20mA signal
- The sensor is an LDR in combination with a ressistor (value = 1200 - 6000 ohms)


When I configure it like picture 1, i don't get anything in my VAT.

When I configure it like picture 2, i get a signal but it's only 0,2 mA. When i measure it without the plc (just 24VDC + LDR + resitor) i get a 4 - 20mA signal.

Are there any hardware or software adjustments that i have to do?

Thanks in advance !

Picture 1 :




Picture 2 :

On the side or back of your card there is a resistor brick that has to be taken out and put into the right position (matching arrows). The position must correspond with that in the HWManager, and match 20mA measurement. There are 2 types of 4-20mA measurements; loop powered (picture 2) and externally powered. Your card might be configurable to power the loop as in picture 1, check in the HWManager.


With a grain of salt (not having the gear here)

Kalle

When i wire up the analog module i get a SF red led.

Connections :

- 1 (L+) = 24VDC
- 11 (Mana) = 0VDC
- 20 (M) = 0VDC

When I select Volt choice in HW config, i have no fault
When I select Deactiviated in HW config, i have no fault
When I select Current (2 or 4 wire connect) in HW config, i have a fault

Anyone know what i do wrong?

BoTJe_84 said:

When i wire up the analog module i get a SF red led.

Connections :

- 1 (L+) = 24VDC
- 11 (Mana) = 0VDC
- 20 (M) = 0VDC

When I select Volt choice in HW config, i have no fault
When I select Deactiviated in HW config, i have no fault
When I select Current (2 or 4 wire connect) in HW config, i have a fault

Anyone know what i do wrong?

Click to expand...

In HWmanager; did you uncheck for 'Wire Break'? (Assuming that all mA inputs are not connected.)

Kalle