Hamilton Electronics EPHUM011 - Manual (Page 21)

pH ARC Sensors Modbus RTU Programmer ’ s Manual (EPHUM011)
624300/01 page 21 / 67
2.5.2.3 Reading the measurement value of PMC1
Register 2090 is also used to read the measurement values of PMC1.
Start
reg. Num-
ber of
reg. Reg1 /
Reg2 Reg3 /
Reg4 Reg5 /
Reg6 Reg7 /
Reg8 Reg9 /
Reg10 Modbus
function
code Read
access Write
access
2090 10 Selected
physical
unit Measure
-ment
value of
PMC1
(1)
Measure
-ment
status
(2)
Min
allowed
value
(1)
Max
allowed
value
(1)
3, 4 U/A/S none
Figure 2.5.2.3.1: Definition of register 2090. Measurement value of PMC1.
(1)
Value is always in the physical unit defined in register 2090.
(2)
Definition of the status see chapter 2.5.4. All bits set to zero means: no problem.
Command: PMC1 read Modbus address: 2090 Length: 10 Type: 3 Read
Parameter: Unit Value Status Min limit Max limit
Format: Hex Float Hex Float Float
Value: 0x1000 4.02503 0x00 0 14
Figure 2.5.2.3.2: Example to read register 2090. Physical unit is set to pH (0x1000), PMC1 is pH
4.02503, Status is 0x00, Min allowed value is pH 0, Max allowed value is pH 14.
Command: PMC1 read Modbus address: 2090 Length: 10 Type: 3 Read
Parameter: Unit Value Status Min limit Max limit
Format: Hex Float Hex Float Float
Value: 0x200000 175.9922 0x00 0 954.6541
Figure 2.5.2.3.3: Example to read register 2090. Physical unit is set to mV (0x200000), PMC1 is
175.9922 mV, Status is 0x00, Min allowed value is -414.0028 mV, Max allowed value is
414.0028 mV.
For the definition of the measurement status see chapter 2.5.4.
Attention:
You cannot read selectively the registers 3 and 4 for the measurement value only. You have to read the
entire length of the command (10 registers) and extract the desired information.