Is it possible to set a RS485 address on the RS485 Node Serial Network Communications Module SN65HVD12D?

General Discussion
1

I am trying to connect multiple RS485 devices together on the same bus. Is it possible to set a RS485 address on the RS485 Node Serial Network Communications Module SN65HVD12D and connect it to the same bus?

2

Hi,
You will need modbus version of this device.

Thanks

3

Do you mean a modbus version of the RS485 Node Serial Network Communications Module SN65HVD12D or a modbus version of the NCD device the RS485 Node Serial Network Communications Module SN65HVD12D is sitting on?

4

modbus version of this. while placing the order add this in the order notes " need Modbus version". we can set address before shipping as well.

Are you using these with relay boards ?

5

Okay thank you! Yes, relay boards and DIO boards.

6

Is it possible to modify what we have in hand to work with RS485 modbus? We have a short time line so if there is a possible software solution that may be quicker.

7

@ryan1 can he use E3C addressing to talk to each relay board ?

8

NCD relay boards support E3C device communications, this allows you to enable/disable devices using commands. Each controller needs to be programmed with a unique E3C device number. The commands are shown in the following guide (though we no-longer sell the hardware shown in this guide as it was not a widely used protocol):

9

Will the E3C device number work the same as a RS485 address? We have multiple RS485 Modubus RTU devices all connected on the same bus by using multiple RS485 hubs. We have 2 RS485 Node Serial Network Communications Modules (SN65HVD12D) we are trying to put on that same bus.

10

yes it will. you will need to set the address to different address.

I will recommend ordering two new RS485 modules with modbus firmware and address. that might be the fastest path forward.

11

If we order 2 new RS485 modules (with modbus firmware) per board that we already have, is there anything extra we have to do to the DIO boards and/or Relay boards other than swapping out the RS485 modules?

Also, how do we communicate with the new RS485 modbus modules? Is there documentation somewhere that lists the modbus command set or examples?

12

@Bhaskar or @ryan1, thoughts on the above questions?

13

we will run some tests here and let you know in next couple of days.

14

Just wanted to follow back up. What were the results from the tests you ran last week?

15

@Bhaskar or @ryan1, just wanted to follow back up. Any results yet?

Also, is there a better form of communication we can reach you at?

Thanks!

16

This is not a combination that has been extensively tested, I think it would be difficult for us to support this configuration. It would probably be best to find a different solution for your application.