Section 1 - Introduction
Installation and Operation Manual
X-DPT-RS485-GF100-Series-MFC-eng
Part Number: 541B183AAG
March, 2020
Brooks RS485 L-Protocol MFCs
1. Introduction
1.1. Purpose
The purpose of this document is to outline the generic RS485 multi-drop
communication protocol for UNIT digital MFC.
1.2. Scope
This protocol is intended to serve all digital MFCs. Only the following
messages are supported:
•
Query for MAC
– Master controller will use this message to query the
existence of a MFC controller.
•
Digital mode selection
– Master controller will use this message to set a
MFC controller to digital mode.
•
Freeze Follow
– Master controller will use this message to configure a
MFC controller to act upon a new set point when received.
•
Set Point
– Master controller will use this message to send a new set
point to a MFC controller.
•
Ramp Time
– Master controller will use this message to send a ramp
time to a MFC controller.
•
Filtered Set Point
– Master controller will use this message to get the
current set point from a MFC controller.
•
Indicated Flow - Master controller will use this message to get the current
flow reading from a MFC controller.
•
Valve Drive Current - Master controller will use this message to get the
valve drive current.
•
Calibration Instance (Process Gas) Selection - Master controller will use
this message to select which calibration instance is to be used for flow
metering.
•
Query for Calibration Instance (Process Gas) Selected - Master
controller will use this message to query the selected calibration
instance, which is currently being used for flow metering.
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