Bender ISOMETER iso1685FR, Manual

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Device communication
33 iso1685FR(M)_D00002_02_M_XXEN/06.2017
General description of a BMS Master
A master can query all measured values, alarm and operating messages from a slave.
If bus address 1 is assigned to a device, this device automatically represents the master, i.e. all addresses bet-
ween 1 and 150 are cyclically scanned via the BMS bus for alarm and operating messages. If the master receives
no answer from 5 subsequent addresses, the scanning cycle will start again. If the master recognises incorrect
answers from a slave, the fault message "Fault RS-485" will be output via the BMS bus.
Fault causes may be:
• Addresses are assigned twice
• A second master exists on the BMS bus
• Interference signals occur on the bus lines
• A defective device is connected to the bus
• Terminating resistors are not activated or connected
6.1.4 Commissioning of an RS-485 network with BMS protocol
• Interconnect terminals A and B of all bus devices in one line
• Switch the terminating resistors on at the start and the end of the RS-485 network. If a device at the end
of the bus is not terminated, connect a 120 Ω resistor to terminals A and B
• Switch the supply voltage on
• Assign the master function and address 1 to a bus-capable device
• Assign addresses (2...33) to all other bus devices in consecutive order.
6.1.5 Setting BMS address
The factory setting of the BMS address can be changed using the DIP switch S
S8103
. Factory setting BMS ad-
dress = 2
DIP-Schalter (SS8103)
BMS- Adr. A4 A3 A2 A1 A0
2 0 0 0 0 0
3 0 0 0 0 1
4 0 0 0 1 0
5 0 0 0 1 1
6 0 0 1 0 0
7 0 0 1 0 1
8 0 0 1 1 0
9 0 0 1 1 1
10 0 1 0 0 0
.. .. .. .. .. ..
… … … … … …
33 1 1 1 1 1
O
A4
A3
A2
A1
A0
1
2
3
4
5
6
7
8