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Series 380 Impeller Btu System
RS-485 Network Configurations
The RS-485 Section can be configured in two ways:
- Modbus
- BACnet
The following sections explain each in detail.
RS-485 Network Configurations– Modbus
Figure 4: Comm Parameters - Modbus
Select
Modbus
, to access the Modbus pull down menus.
Select the
Address
,
Bit Rate
(Baud Rate) and
Mode
(RTU or ASCII).
The Series 380 uses IEEE 754 Float - Data Located in “Read Holding Registers.”
The Series 380 Data Format is “Float 32” where the Data is stored across two “Read Holding Registers”.
In the case of sensor mounted in the 380 body, the upper byte is stored in register 40001 and the lower byte is stored in the
register 40002.
For example, a temperature of 53.36°F when converted to IEEE 754 is “425570A4.” In the case of the Series 380, Register #
40001 = 70A4 Hex and Register # 40002 = 4255 Hex. See the table on the next page for additional information.
