pH ARC SensorsModbus RTU Programmer’s Manual (EPHUM011)
624300/01 page 10/ 67
2.4.3 Description of the Analog Interfaces 1 and 2
Register 4352/ 4480contain the descriptions of AO1 / AO2 as plain text ASCII:
Start
register Number of
registers Reg1…Reg8
16 ASCII characters Modbus
function code Read
access Write
access
4352 8 Description of AO1 3, 4 U/A/S none
4480 8 Description of AO2 3, 4 U/A/S none
Figure 2.4.2.1: Definitionof register 4352 and 4480
Command: Currentinterface text Modbusaddress: 4352 Length: 8Type: 3Read
Parameter: Text
Format: Character
Value: mAin terface #1
Figure 2.4.2.2:Example to read the description of AO1. The text is “mA interface #1”. Accordingly,
AO1 is physically configured as a 4-20 mA current output.
Command: Currentinterface text Modbusaddress: 4480 Length: 8Type: 3Read
Parameter: Text
Format: Character
Value: mAin terface#2
Figure 2.4.2.3:Example to read the description of AO2. The text is “mA interface #2”. Accordingly,
AO2 is physically configured as a 4-20 mA current output.
Attention:
pH ARC Sensorsdo not have an ECS (in contrast to VISIFERM DO)!
Data structure: registeraddress offset between AO1 and AO2 is always 128.
2.4.4 Selection of an Analog Interface Mode
The analog interfacem ode of AO1 / AO2 is selected by programming the analog interface mode in
register 4360/ 4488.
Start
register Number of
registers Reg1/ Reg2 Modbus
function code Read
access Write
access
4360 2 Active analoginterface mode for AO1 3,4, 16 U/A/S S
4488 2 Active analog interfacem ode for AO2 3,4, 16 U/A/S S
Figure 2.4.4.1: Definitionof register 4360 / 4488. Only one bit can be set.
Command: Active interfacem ode Modbus address: 4360 Length: 2Type: 16 Write
Parameter: Mode
Format: Hex
Value: 0x02
Figure 2.4.4.2: Example to set the analog interface mode of AO1 to 0x02 (4-20 mA linear output).