Hamilton Electronics EPHUM011 - Manual (Page 22)

pH ARC Sensors Modbus RTU Programmer ’ s Manual (EPHUM011)
624300/01 page 22 / 67
2.5.3 Primary Measurement Channel 6 (Temperature)
2.5.3.1 Description of PMC6
In register 2400, a plain text ASCII description of PMC6 is given
Start
register Number of
registers Reg1 … Reg8
16 ASCII characters
Modbus
function code Read
access Write
access
2400 8 Description of PMC6 3, 4 U/A/S none
Figure 2.5.3.1.1: Definition of register 2400.
Command: PMC6 text Modbus address: 2400 Length: 8 Type: 3 Read
Parameter: Text
Format: Character
Value: T
Figure 2.5.3.1.2: Example to read the description. It is “ T ”(Temperature).
2.5.3.2 Selecting the Physical Unit for PMC6
In register 2408, the available physical units of PMC6 are defined.
Start
register Number of
registers Reg1 / Reg2
(bitwise defined) Modbus
function code Read
access Write
access
2408 2 Available physical units of PMC6 3, 4 U/A/S none
Figure 2.5.3.2.1: Definition of register 2408.
Command: PMC6 available units Modbus address: 2408 Length: 2 Type: 3 Read
Parameter: Units
Format: Hex
Value:
0x06
Figure 2.5.3.2.2: Example to read the available physical unit for PMC6. K (0x02) + °C (0x04), total
0x06.
In register 2410, the active physical unit of PMC6 can be selected, by choosing one of the physical
units that are defined in register 2408.
Start
register Number of
registers Reg1 / Reg2
(bitwise defined) Modbus
function code Read
access Write
access
2410 2 Selected active physical unit of PMC6 16 none U/A/S
Figure 2.5.3.2.3: Definition of register 2410. Only one bit can be set.
Command: PMC6 set unit Modbus address: 2410 Length: 2 Type: 16 Write
Parameter: Unit
Format: Hex
Value: 0x04
Figure 2.5.3.2.4: Example to set the physical unit of PMC6 to °C (0x04).
Attention:
Changing the physical unit has also an influence on the output of AO1 / AO2, as the same physical unit
is active for the analog outputs. All limits of the 4-20 mA analog output have to be redefined after
changing the physical unit!