pH ARC Sensors Modbus RTU Programmer’s Manual (EPHUM011)
2.4.3 Description of the Analog Interfaces 1 and 2
Register 4352 / 4480 contain the descriptions of AO1 / AO2 as plain text ASCII:
Start | Number of | Reg1 … Reg8 | Modbus | Read | Write |
register | registers | 16 ASCII characters | function code | access | 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: Definition of register 4352 and 4480
Command: Current interface text | Modbus address: 4352 | Length: 8 | Type: 3 | Read | |||
Parameter: | Text |
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Format: | Character |
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Value: | mA interface #1 |
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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: Current interface text | Modbus address: 4480 | Length: 8 | Type: 3 | Read | |||
Parameter: | Text |
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Format: | Character |
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Value: | mA interface #2 |
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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 Sensors do not have an ECS (in contrast to VISIFERM DO)!
Data structure: register address offset between AO1 and AO2 is always 128.
2.4.4Selection of an Analog Interface Mode
The analog interface mode of AO1 / AO2 is selected by programming the analog interface mode in register 4360 / 4488.
Start |
| Number of | Reg1 / Reg2 |
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| Modbus |
| Read | Write | |||
register |
| registers |
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| function code |
| access | access | ||
4360 |
| 2 |
| Active analog interface mode for AO1 | 3, 4, 16 |
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| U/A/S | S | |||
4488 |
| 2 |
| Active analog interface mode for AO2 | 3, 4, 16 |
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| U/A/S | S | |||
Figure 2.4.4.1: Definition of register 4360 / 4488. Only one bit can be set. |
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Command: Active interface mode | Modbus address: 4360 | Length: 2 |
| Type: 16 | Write | |||||||
Parameter: |
| Mode |
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Format: |
| Hex |
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Value: |
| 0x02 |
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Figure 2.4.4.2: Example to set the analog interface mode of AO1 to 0x02 (4-20 mA linear output).
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