How to prepare Multiple Meter communication interface?

Hello vandana_49, your question needs to be more detailed.

Nonetheless, I do not think that optic cable is optimal decision for your project.

I am sure that using only RS232 directly is worst of options. RS232 protocol is not fitted to be transmitted on distance greater than some 3 m. Long time ago I used RS232 (current loop) industrial protocol --- but one hadn't been network adopted and now is obsolete.

If I were you I would collect this network by means of RS485 adapters. RS485 half-duplex protocol can be transmitted up to 1,2 km without need to apply repeater.

There could be applied Ethernet, but it restricted in distance about 100-150 m between nodes. As well for your project unlikely needed high-speed connection. Even 9600 b/s of RS485 is likely enough.

You can consider option of RS422 (full duplex) but it demands an additional wire (1 or 2) for your cable.

regards,

caramba

Hello,

Thanks for the reply.

But, to be more elaborate, I need this setup to be used on my production floor, all 40 meters shall me mounted on a power-up bench in close vicinity. That's why, RS485 and Ethernet are not my choices. If i use RS232 directly from CPU through this multiplexer (that I want to design) to all the meters, will that be possible?

So, please reply, if you have an option.

Thanks

Vandana

If you encourage yourself to make multiplexer I bow my head before you as I am too lazy now to create such things. But it's ok. You want do it so you can. Technically it's possible to make 40 channel multiplexer for RS-232 (I recommend you do one galvanicaly insulated from PC and meters ports). But I wonder how do you plan to place 40 meters on distance which not exceeds 3 m from multiplexer?

Next point. What kind of communication protocol has your meter who is its vendor? It seems they have embedded 232 port as it is the only reason you got stuck on it.

Oops! I recollect that there was similar decision. Are you intending to use your multiplexer just as ordinal dial-up modem for collecting data from meters? It is possible. But I prefer 485 or Modbus.

caramba

I must agree with Caramba, rs485 / or ethernet are the best options.. We have in the past had relays with RS232 comms only, and we used RS232 to RS485 converters to get around this obstacle, or vice versa.. If you want to connect your laptop at central location you daisy chain all your Modbus Comms together, and at the end you connect your RS485 - RS232 converter and plug in pc..

hello vandana,

I think you are in meter industry & now you want to calibrate all these 40 meters on test bench at a single shot.

is it the case?