Bronkhorst®
Instruction Manual EL-FLOW® Select
9.17.099J
16
2.7.2
Modbus
Modbus is a 3-wire, RS-485-based fieldbus communication system for parameter value exchange. In this system each
instrument/device is equipped with a micro-controller for its own dedicated task. The instrument behaves as a slave, which
means all communication (instructions and readout) is initiated by a master device on the Modbus system.
Characteristics:
·
Baud rate selectable between 9600 and 256000 Baud (default: 19200 Baud)
·
+15…24 Vdc supply voltage
·
Connection of up to 247 instruments on a single bus
·
Supports RTU and ASCII protocols
Consult
Instruction manual Modbus interface
(document no. 9.17.035) for more information about setting up a
Modbus network.
2.7.3
Other fieldbuses
For other fieldbuses consult the concerning
2.8
Communication interface
The standard 9-pin D-sub connector provides the following communication interfaces:
·
Analog (0…5 Vdc; 0…10 Vdc; 0…20 mA or 4…20 mA)
·
Digital RS-232 (
) or RS-485 (FLOW-BUS or Modbus)
