Tuesday, June 16, 2009

MODBUS Device Looping and Pinouts

Writing a software to read a MODBUS device is not a tough task as far as the top level application is concern. There are many open-source library available to wrap-on. The crucial and "not fitting in the bottle" task is the cabling requirement to make the device loops working.




MODBUS looping configuration


Points to remember

1. MODBUS looping is only possible with RS422/RS485 and not with RS232 . In general approach is using RS485.

2. You need to check what connectors are available at the device end. Say both have Serial (DB9) or one have DB9 and other have RJ11 or RJ45. Then ofcource the cable is required accordingly.

3. You also need to know what pinout is required for cable connection.
e.g. You have DB9 and RJ11 connector at device end, so a cable with Serial (DB9) to RJ11 required. Now the point to worry is DB9 with 9 pins and RJ11 with 6 pins.
A typical pin-out would look like....


(RS485 to RJ11 Pin-out)


Your device may not be working with the above configuration, so you need to check with the device vendor at which pin they would be taking (-, +, g(ground)). Do take care of the cabling part as it is a big problem while using different connectors.

1 comment:

  1. European gamers face solely a 2.7 p.c edge, and that's lowered to 1.4 p.c on even-money bets by a rule called en prison, which is described later on this article. At 1.4 p.c, roulette becomes aggressive with different casino games; at 5.26 p.c, it's a very troublesome recreation to beat. Multi-Wheel Roulette takes full benefit of its on-line capabilities to deliver quantity of} games at once. Instead of putting your chips and ready, you can to|you probably can} maintain the action going throughout completely different 카지노사이트 wheels. But ought to use|you must use} that table to bet throughout quantity of} spinning roulette wheels, usually positioned simply above the table.

    ReplyDelete