Modbus MFU Option Card Installation Manual
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Publication PUB091-004-00_0918
2.2 Electrical Properties
The MFU processor circuits communicate to other modules in the actuator via an internal
communications bus. The MFU does not sit in the main control path for the actuator and does not
affect the actuator control integrity. The MFU processor contains the firmware for the unit. The
firmware version is indicated on the label fitted to the processor. It can also be read from the actuator
using the setting tool, by using Insight with Infra-red or by using Insight2 with Bluetooth, where
appropriate.
Additionally, the circuit includes non-volatile memory that is used to store specific field unit
communications settings.
The Modbus RS-485 fieldbus data highway connections are fully isolated from the actuator
electronics.
2.3 Operation and Storage
The MFU is designed to be stored in the actuator and operated within the same environment as the
actuator. The constraints are:
Operating temperature: -40deg C to +70deg C
Storage temperature:
-50deg C to +85deg C
Relative Humidity:
5% to 95% (<50deg C) non-condensing
