S7-200 High Speed Counter for Encoder Input

I've read the Siemens website article for programming a high speed counter to read an encoder. Being that I am new to the S7, I was wondering if anyone has a circuit wiring diagram of a typical encoder hookup to the S7-200. Or possibly a link that shows the hookup. Thank you.

Does one just pick a normal digital input and configure it in the software as a high speed counter input? Or is the high speed counter a separate special add-on module?

The high speed counter function is available for 2 to 6 digital inputs (depending on CPU type) located on the CPU module. You have to use some special instructions to enable these functions. Some assitent in Microwin (the S7-200 programming software) will do most of the work for you.
Wiring:
The inputs take 24V DC pulse signals up to some 10KHz. It is possible to configure h.s.counters as up/down counters using encoders with 0 and 90 degree signals (don't remember the english term at the moment) wiring the signals to a pair of inputs.

Depending on the model of S7-200 you have, there are several different counter configurations available. There are no additional modules required but you do need to know which inputs are associated with your selected configuration. The 221 and 222 have up to 4 counters, the 224 and 226 models have up to 6. The mode of operation (up, down, up/down, single/double/quadrature etc) can be defined using a specific software instruction HDEF, or by using the Counter Wizard in the S7-200 microWin software. In your code, when you then come to address and control the counter operation, you use the instruction HSC.

I don't know which of the many (no, make that very many) Siemens' website articles you've read, but getting the S7-200 manual is essential here. Try http://support.automation.siemens.com/GB/news/en/1109582

regards

Ken.

(Us Ken's have got to stick together!)

An easier way to configure the HSC is to use the HSC wizard in MicroWin. Go to Tools> Instruction wizard and choose HSC.

For wiring, you would just connect the encoder to the input(s) based on the type of HSC you use.

Refer the attached pdf

Aahh, right. So, "to use the HSC wizard in MicroWin" would be an easier way than "using the Counter Wizard in the S7-200 microWin software" then? Just making sure we don't confuse the issue for Ken.


Ken

Thanks for the info. I found some other info today. Since the S7-224 input requires a sourcing device(driven by PNP transistor) and the encoder requires a sinking device(NPN transistor) I will have to use a 12 volt NPN to PNP converter between the encoder and PLC input.

I have the Siemens Systems Manual which has an example for programming a high speed counter. However, I still intend to read the info in the links you guys provided me.

One other question for you guys. I uploaded a program from a S7-224 using an older version of the Siemens software on my laptop(windows 98). I have version 4.0 installed on my desk top computer(XP). Is it possible to import the symbols and text comments from a program on my desk top computer to the uploaded program on my laptop? Note: both programs are nearly identical, but not mirror images since one runs on the newer version and the other on the older version of the Siemens software. Also, I noticed that one of the programs could not be opened by the other version of the Siemens software. What is the directory that stores the symbols and text in the ladder logic or what is it called?

Check the S7-200 documentation; the S7-224 can accept both NPN and PNP inputs. It depends on whether you connect +ve or -ve to the common. There are 2 commons on S7-224: 1M and 2M for inputs I0.x and I1.x respectively. You could use inputs common to 1M as NPN and inputs common to 2M as PNP.

I am not sure if there is any better way, but I simply copy the symbols on the symbol table. Just click on the symbol table (View>Component>Symbol table). Select all the cells and copy. You could paste it on the other program that was uploaded from the PLC. Hope this helps Ken J...

Ken M - you got me there Man!

Thanks Preeya. That's some good infomation you gave me that I wasn't aware of.