Loosing my sanity - TIA & SM 1232 AQ4

[MrQ]

Hi,

I have spent half my day with fever trying to figure out the SM 1232 AQ4 in TIA Portal.

I have configured the output chanel0(QW144) to voltage. I have downloaded hw config and restarted PLC.

I try changing the output value 0-27648

If I only have a multimeter connected it reads 0V no matter what.

If I have the 0-10V input of my valve amplifier connected and my multimeter in paralell it reads 0-4V. This is where I would like to see 0-10V.

All led are green. No error in diagnostics. What am I missing??

 

[cardosocea]

How is it configured?

 

[MrQ]

It's configured for voltage output +/-0-10V. Not much more to set than short circuit diagnostics or am I missing something?

 

[JesperMP]

Have you provided the module with 24V supply on the terminals L+ and M ?

edit: Investigate the diagnostics. If supply voltage is low there should be a diagnostic entry.

 

[cardosocea]

Wouldn't the light on the module turn red though?

 

[L D[AR2P#0.0]]

Show us the electrical schematic of how it is wired.

 

[BryanG]

Have spent 1/2 days myself getting very frustrated, I was often even more frustrated when I realised it was me doing stuff wrong . So just in case

You say you connect your multimeter, can you confirm where you are connecting it. Just trying to check that you are using a common reference, the analogue 0V on the PLC is floating unless you tie it down.

I have in the past tried measuring a DC voltage with the multimeter set to AC, or the leads in the current instead of voltage connections.

I found that one of my multimeter leads had a bad connection, it was high resistance, so voltages were wrong.

I have had the S7-1200 start doing weird things after many online updates, I could see the right value on the screen, but what was coming out was wrong. I did try screaming at the PLC that the value was right, but it didn't take any notice. Eventually I did a Factory Reset, reloaded, and everything suddenly worked.

 

[cardosocea]

I have in the past tried measuring a DC voltage with the multimeter set to AC, or the leads in the current instead of voltage connections.

You forgot the inevitable broken fuse on your multimeter...

 

[MrQ]

Have you provided the module with 24V supply on the terminals L+ and M ?

edit: Investigate the diagnostics. If supply voltage is low there should be a diagnostic entry.

I measured 24.2 Volts between L+ and M. No diagnostic entry.

 

[MrQ]

Show us the electrical schematic of how it is wired.

It is really done by the book. However only the first chanel is used.

https://support.industry.siemens.co...1435&imageName=46372573451.PNG&Language=en-US

 

[MrQ]

You forgot the inevitable broken fuse on your multimeter...

Tried two multimeters and with both I could measure 24V on the suply.

 

[MrQ]

Have spent 1/2 days myself getting very frustrated, I was often even more frustrated when I realised it was me doing stuff wrong . So just in case

You say you connect your multimeter, can you confirm where you are connecting it. Just trying to check that you are using a common reference, the analogue 0V on the PLC is floating unless you tie it down.

I have in the past tried measuring a DC voltage with the multimeter set to AC, or the leads in the current instead of voltage connections.

I found that one of my multimeter leads had a bad connection, it was high resistance, so voltages were wrong.

I have had the S7-1200 start doing weird things after many online updates, I could see the right value on the screen, but what was coming out was wrong. I did try screaming at the PLC that the value was right, but it didn't take any notice. Eventually I did a Factory Reset, reloaded, and everything suddenly worked.

I am very thankful for your response. I have a bad cold and stayed at home in bed today. Yesterday my brain was a little fied.

However:

I connect on the AO terminals 0 and 0m. I disconnect them from my circuit and then I suppose i should really be able to measure 0-10V without interference.

I have tried two multimeters and with both I can measure the 24V suply.

I am sure I am measuring DC with both and I can measure the 24V suply.

I was to tired yesterday to scream and bang but I'll try taht and a complete Factory reset.

 

[MrQ]

One thought.

The AO was originally configured as Current 4-20mA.

I changed config to 0-10V and havre downloaded the HW config to the PLC. Can it somehow still be configured as a Current 4-20mA???????????

When I have nothing connected to the AO i can read no Voltage with my Multimeter. When i connect my device with an AI I can read up to 4V in paralell.

 

[JRW]

Are you sure you downloaded the hw config
Also , do all the channels act the same?
Try other channels

 

[dwoodlock]

One thought.

The AO was originally configured as Current 4-20mA.

I changed config to 0-10V and havre downloaded the HW config to the PLC. Can it somehow still be configured as a Current 4-20mA???????????

if this were the case and you pushed 27XXX to it and its functional, you would still read a voltage in my experience, but not what voltage you expected.