PRODUCT MANUAL - BARIX X8 - V01.05 - 10/26/2006
Modbus Register Map
The BARIX X8 implements some registers in the Modbus address
space. Access to unimplemented locations generates an
exception.
The Modbus address space is divided into multiple address maps,
all 65536 registers in size. The BARIX X8 implements the
coils (output bits) and the registers (16 bit).
Reading back discrete (1bit) values is not supported.
Attention: All Modbus addresses count from 1, while the
protocol addresses start at 0. This documentation uses the
Modbus register number in the protocol the address must
be one less !!
Example:
Modbus register 1 is addressed in Modbus/RTU as 0.
The state of the outputs can be set/reset using set coil and
write register commands. In addition, the state of the outputs
can be read back using the read register command.
In the coil address map, only positions 1..8 (Modbus/RTU
addresses 0..7) are populated in the BARIX X8, which are
mapped to outputs 1..8. Write access to any other address is
prohibited.
In the register address map, the outputs can be written
simultaneously by accessing register 1. Bit 0 is output 1, bit 1 is
output 2, ... bit 7 is output 8.
The state of the inputs 0 to 7 can be read using the read input
register command on register 2 (see corresponding Bits 0 to 7).
The analog values (10bit res. [0..1023] / sampling rate 62.5 Hz) of
each input can be read using the read input register command
on register 3 (input 0) to 10 (input 7).
When a Barix TS temperature sensor is connected the analog
voltage is replaced by the temperature (for each attached
sensor)!
Modbus Register Map · 17
Live I/O
