IRDH275BM-7_D00123_07_M_XXEN / 08/2020 31
ISOMETER® IRDH275BM-7
5.3.3 Commissioning of an RS-485 network with BMS protocol
• Connect the terminals A and B of all bus nodes in one line
• Switch the terminating resistors on at the beginning and end of the RS-485 network or in case
of devices without a terminating switch, at the end of the bus, connect a 120 resistor to the
terminals A and B.
• Switch the supply voltage US on.
• Determine one IRDH275B as the Master and assign address 1.
• Assign the addresses (2…30) subsequently to all other IRDH275B devices and other bus
nodes (see table below).
• Check whether a flashing point appears on all devices (BMS commands are being received).
BMS-bus adress ranges
Adresses
Device
Meaning
0
There is no device with address 0 !
Information sent to address 0 applies to all
devices connected to the interface (broadcast)
1
PRC1470
Control and indicating device
1...30
IRDH275B/ 375B/575
Insulation monitoring device
1...30
COM465
Protocol converter
2...30
EDS47x-12
Insulation fault evaluators (localisation)
31...60
SMO480-12
Signal converter relay
61...90
EDS47xE-12
Insulation fault evaluators (localisation)
111...119
PGH47x
Test device for insulation fault location
121...150
PGH47xE
Test device for insulation fault location
i
Malfunctions due to wrong address assignment! Assigning wrong addresses to external devices may
cause malfunctions. Assign the addresses in a way that there are no gaps of more than five subse-
quent addresses (1…30, 31…60, 61…90, 111…119 and 121...151).
