XLINK 500/100 Operations & Maintenance Manual page # 172
The Device ID is the address that is used by the Modbus master to select which device to
communicate with. Each slave on the bus must have a unique device ID ranging from 1
–
247.
Address ‘0’ is reserved as the broadcast address.
When a Modbus master issues a command, it includes the Device ID in the command. Only the
Modbus slave with a matching ID is allowed to answer. If multiple slaves have the same ID,
communication will not work.
Device ID is sometimes referred to as Slave Address, Station Address, or Slave ID.
Modbus Baud Rate
Default is 19200 Baud. Care must be taken to make sure the selected speed matches that of the
master or there will be communication problems.
This setting affects both Modbus master and Modbus slave.
Modbus Parity
Default is Even. Available choices include Even, Odd and None.
Note: Care must be taken to make sure the selected parity matches that of the master or there
will be communication problems.
This setting affects both Modbus master and Modbus slave.
Modbus Slave Delay before Tx
Default is 0ms. This identifies the number of milliseconds to wait before starting data
transmission. This is useful if the device is connected to a radio requires keying initialization
before data transmission.
This is a Modbus slave setting only. There is no delay when the station is a Modbus master.
Modbus Slave Delay after Tx
Default is 0ms. This identifies the number of milliseconds to wait after data transmission. This is
useful if the device is connected to a radio that requires a hold-off time after data transmission
has completed.
If this value is other than zero, it may cause communications issues!
This is a Modbus slave setting only. There is no delay when the station is a Modbus master.
18.3.2.
Modbus Measurement Settings
These settings appear on the Measurement tab of LinkComm. To have the station act as a
Modbus master, choose Modbus as the Measurement Type.
Modbus Port
This is a measurement setting that tells the station which port the Modbus sensor is connected
to. Options include RS-485 and RS-232.
Modbus Device Id
Modbus Device Id indicates what sensor to collect data from. For the station to collect data from
a Modbus slave, the station
’s Modbus Device Id must match that of the sensor.
This setting should come into play only if there are multiple sensors on the bus.