Ask about CPU S7200/300 PLC


Thread Starter

pham d.thanh

I’m working in Power Tranmission Company N03-Viet Nam Country.

I’m looking for devices about CPU of SIMATIC S7-200 and S7-300. Alsmost all your product which you manufactured with CPU kind of:
Power supply: 24VDC
Input digital: 24VDC
Output digital: 24VDC/ max 2A.

While I need CPU & module I/O kind of:

Power supply: 220VDC

Input digital: 220 VDC

Output digital: 220VDC/ max 5A.

So, You can inform me if you manufactured produces which I need above and give me a consultancy about this problem. <

Daniel Chartier

Hello Mr. pham;
first, here is a link to Siemens' system manual for the S7-200:


In the appendices, there are specs for the different CPU and expansion modules.
CPus are available with 220 V AC power suppluy and relay outputs (rated 2 A, with surge current support up to 5 a); but integrated inputs on the CPU are only 24 V DC.
However, look at expansion modules:
-6ES7221-1EF22-0XA0 is an 8DI, 120/220 VAc input module
-6ES7222-1HD22-0XA0 is a 4DO, relay, 10A output module (6ES7222-1HF22-0XA0 is a 8DOrelay output, 10 A).

So with the 27-200 you cannont use a stand-alone brick CPU to attain your objectives. But you vcan use expansion modules.

Hope this helps,
Daniel Chartier

Michael Griffin

220VDC would be very unusual for a PLC. To use conventional 24VDC PLC I/O, you could place solid state relays or opto-couplers between the field devices and the PLC. Look for solid state relays or opto-couplers from companies such as Phoenix.

For powering the PLC, you will either need to supply power from another source, or find a DC/DC converter that will convert the 220VDC to 24VDC.

marc sinclair


Sorry, The original poster did say clearly 220VDC - my fault.

It may well be worth contacting Siemens though, if the PSU has a switching input, it may well work OK from 220vdc.

I used to use a car inverter which gave out 300vdc for a 220vac laptop.

Marc Sinclair