Hamilton Electronics EPHUM011 - Manual (Page 12)

pH ARC Sensors Modbus RTU Programmer ’ s Manual (EPHUM011)
624300/01 page 12 / 67
2.4.5.3 Reading the Minimum and Maximum Possible Physical Output Current
Start
register Number of
registers Reg1 / Reg2 Reg3 / Reg4 Modbus
function code Read
access Write
access
4366 4 Min physical
output current
for AO1 [mA] Max physical
output current
for AO1 [mA] 3, 4 U/A/S none
4494 4 Min physical
output current
for AO2 [mA] Max physical
output current
for AO2 [mA] 3, 4 U/A/S none
Figure 2.4.5.3.1: Definition of register 4366 / 4494
Command: Limits AO1 Modbus address: 4366 Length: 4 Type: 3
Read
Parameter: Min limit [mA] Max limit [mA]
Format: Float Float
Value: 3.5 22
Figure 2.4.5.3.2: Example to read the min and max output current of AO1. Min is fixed to 3.5 and Max
is fixed to 22 mA (Currents above 20 and below 4 mA indicate erroneous measurements or
errors).
The same values are stored in register 4494 for AO2.
2.4.5.4 Reading the Minimum, Maximum and Mid Current for Measurement Value Output
Start
register Number of
registers Reg1 / Reg2 Reg3 / Reg4 Reg5 / Reg6 Modbus
function
code Read
access Write
access
4370 6 Min output for
measurement
value for AO1
[mA] Max output for
measurement
values for AO1
[mA] Mid output
(bilinear) for
measurement
values for
AO1 [mA] 3, 4 U/A/S none
4498 6 Min output for
measurement
value for AO2
[mA] Max output for
measurement
values for AO2
[mA] Mid output
(bilinear) for
measurement
values for
AO2 [mA] 3, 4 U/A/S none
Figure 2.4.5.4.1: Definition of register 4370 / 4498
Command: MinMaxMid current AO1 Modbus address: 4370 Length: 6 Type: 3 Read
Parameter: Min current [mA] Max current [mA] Mid current [mA]
Format: Float Float Float
Value:
4 20 12
Figure 2.4.5.4.2: Example to read the min, max and mid output current for measurement values for
AO1. They are fixed to 4, 20 and 12 mA.
The same values are stored in register 4498 for AO2.
Note:
Mid current must always be defined. However, in linear output mode, the mid current value has no
physical meaning and will not affect the 4-20 mA output.