M172 and SER8300 integration over BACNET MS/TP

[jyoon]

We are trying to connect M172 and SER8300 over BACNET MS/TP using Machine Expert HVAC.  How can we read the anlaog values (Temp and Humidity, etc) using M172 from SER8300?  Currently, SER8300 is connected to M172 RS485-1 (BACNET MS/TP).  We already changed COM (MAC) value from 254 to 10.  Thank you very much for your help!

[CraigEl]

I don't know much about the M172 but from what I can tell it's BACnet MS/TP capabilities are fairly limited. When we use it in Hotel situations we generally connect to the SE8000 using modbus. From SE8000 firmware version 1.3 and later modbus is inbuilt.

You can find the SE8300 Modbus Integration Guide on the Exchange.

You can find the selection of BACnet/Modbus in the SE8000 network menu

[jyoon]

Now we changed it to Modbus. RS485-2 +, - and ground are connected with COM address of 10.  I am having trouble opening up the document link.  Do you have any wiring diagram as well?  I believe I need to install a resistor/resistors at a terminal device but I wasn't sure.  Currently, we only have two devices.  We have M172 on one end and SER8300 on the other.    So do I need to install resistor on both ends?    

Thank you very much for your help!

[CraigEl]

Don't connect the SE8000 ground terminal, I know it's not intuitive...

The following is an extract from a presentation for the Hotel Room Solution (HRC) that is based on the M172. You will want to have a 120 ohm resistor at each end, this is standard practice for RS485.

[jyoon]

Thank you.  I disconnected it now but had it connected before.  Do you think this may have made the equipment inoperarable?  I attached screetshots for configuration of Modbus Slave.  Do I need to have programming file as well?  I don't think I am establishing the serial connection at all.  Thank you.

[GeorgeL]

Hi there, 

Just came across your question. Has it been solved? 

If not, were you able to see the Device present in ESME HVAC software? 

You can do it by dragging Highlighted Target variable to your watch window.

[Majid]

hi , i have m172p 42 io 

I want to use it to connect modbus device variables to bacnet ip network

Please tell me how to read the present value of the bacnet variables to use it in the program