RayTek MI3, Руководство по эксплуатации

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Modbus
88
Rev. F1 05/2013
MI3
15 Modbus
The Modbus protocol follows the master/slave model. One master controls one or more slaves.
Typically, the master sends a request to a slave, which in turn sends a response. The request/response
mechanism is called a transaction. Requests and responses are also referred to as messages.
Specification:
Version: Modbus serial line (RS485)
Mode: RTU (Remote Terminal Unit)
Physical layer: RS485, 2 wire, electrically isolated
Baud rate: 9.6, 19.2, 38.4, 57.6, 115.2 kBit/s
Connection terminal
Address range: 1 to 247 (for the Modbus device)
Parity even
The detailed Modbus specification can be found under http://www.modbus.org/ .
15.1 Wiring
15.1.1 Comm Box (metal)
X1 Pin Terminal Modbus
1 D0
(negative signal)
2 D1
(positive signal)
3 Shield
4 GND
(output, used for external termination)
5 n.a.
6 + 5 V
(output, used for external termination)
L
ED
, yellow ON while communicating
L
ED
, red Error
Figure 76: Modbus Terminal for Comm Box (metal)
The termination for Modbus networks must be realized externally by the user!
1.800.868.7495 info@Raytek-Direct.ca