SLPSLXX needs a modbus line terminator?

[Anonymous user]

I´m working in a project for BMS, where many SLPSLXX are used. Those sensor are coneccted in a modbus net to the RP-C, via sensor bus port. I know that all the modbus lines needs at both ends a 120 ohm resistor, but I didn´t find any document about how to do it on this system.

I would be grateful if someone could confirm if I need the bus end resistor or not.

[PiotrJakubczyk]

Here is explanation

https://e2e.ti.com/blogs_/b/analogwire/posts/rs-485-basics-when-termination-is-necessary-and-how-to-...

But i Think from your point of view it is more important to know this:

The RP-C Modbus network supports up to 10 connected Modbus devices with the following restrictions:

• Maximum of one KNX Modbus gateway (RP-C-EXT-KNX)

• Maximum of 250 Modbus registers

NOTE:

The RP-C Modbus network does not support 64-bit Modbus registers.

https://community.se.com/t5/Building-Automation-Knowledge/What-is-the-BACnet-MSTP-unit-load-of-the-S...

Also 

Ensure that the total length of the room bus does not exceed 72 m

Ensure that the total length of the sensor bus does not exceed 61 m 

Also more proper forum is "

• EcoStruxure Building Operation Forum