ET-200ISP Voltage drop due to long cables

We have DO-signals from 6ES7132-7RD01-0AB0 activating Ex-solenoids, but cables are very long. So our problem is that we experience voltage drop and unreliable solenoid control.

In order to achieve more reliable solenoid control, customer wants to change from ET-200ISP to ET-200M IO-cards (6ES7322-5SD00-0AB0).

I have not found Volt/Amp-curves for the two cards.

Are there Ex-DO cards in Siemens product-line that can improve the situation?

Hello,

you could use switch amplifiers.

https://www.e-direct.endress.com/de/en/namur-isolating-amplifier-nivotester-ftl325n

Regards

Scott

If I would go for EM-200M, the rack will be located in a safe area, but DO-card would be 6ES7322-5SD00-0AB0.

- ET 200M 6ES7322-5SD00-0AB0 can induce 24VDC at 10mA output.

- ISP 6ES7132-7RD01-0AB0 can induce 23,1V at 20mA output.

I do not have the power output / loop impedance curves for the two cards, but it seems to med that ISP is the best after all.

Thank you for your suggestion, but I can't see how I can use a switching amplier. I have Digital outputs from Ex-DO card to Exi field solenoids.

Regards Henry

I think I will have to see if I can use standard DO, adjusted DC/DC converter to optimise the output voltage, and adapted zener barrier.

It seems that I will end up close to safety curves for Ex.