Connectivity of NPN encoder with PLC's HSC Module via optocouplers or SSRs

[Nauman]

Dear Sirs,


An NPN Encoder is connected with a Motor's Shaft and we want to use optocouplers , SSRs or Reed relays at the output of NPN encoder , so that the signal can be readable to the PLC's High Speed Counter module 350-2 of SIEMENS S7-300 PLC. Kindly guide us in this problem that how can we use the optocouplers , SSRs or Reed relays.

Regards

Nauman Pervez

 

[paulcs]

SSR interface

In most cases, the encoder can be connected directly to the 350-2. However, if you need an interface product, a high speed SSR (15Khz speed) is available from http://www.power-io.com/products/hdd.htm
and a slow speed SSR is http://www.crydom.com/userResources/productFamilies/39/crydom_1dc.pdf

Either should be available from stock.

 

[jacekd]

I'd try pull-up resistors first.

 

[Nauman]

Dear Palcs,

Thank you for your prompt reply.We are not sure that whether NPN Encoder can be directly connected to 350-2 Module or not. After that we also want to use an Optocoupler as an interface because its a cheap solution for us.
Please tell us can we use NPN encoders directly to the 350 module or an Octocoupler device should be used as an interface.

Thank you

 

[ArikBY]

Hi

Generaly you dont need any thing btween your encoder and your PLC,You need to set your High Speed Counter module to NPN input and thats it.
If you cannot do so and you must use PNP encoder to fit your module you can use pull up resistor to convert the encoder signal from NPN to PNP.
That the cheapest way (less then $1)