SUPERtrol II Flow Computer
103
9. RS-485 Serial Port (optional)
9.1 RS-485 Port Description:
The SUPERtrol II has a an optional general purpose RS-485 Port which may be used for any
one of the following purposes:
Accessing Process Parameters
Rate, Temperatures, Pressures, Density, Time & Date, Setpoints, etc.
Accessing System Alarms
System, Process, Self Test, Service Test Errors
Accessing Totalizers
Heat, Mass, Corrected Volume, Volume Totalizers and Grand Totalizers
Executing Various Action Routines
Reset Alarms, Reset Totalizers, Print Transaction, Reset Error History,
9.2 General
The optional RS-485 card utilizes Modbus RTU protocol to access a variety of process
parameters and totalizers. In addition, action routines can be executed. For further information,
contact factory and request RS-485 Protocol manual.
9.3 Operation of Serial Communication Port with PC
The flow computer's RS-485 channel supports a number of Modbus RTU commands. Refer
to port pinout (below) for wiring details. Modbus RTU drivers are available from third party
sources for a variety of Man Machine Interface software for IBM compatible PC's.
The user reads and writes information from/to the RS-485 using the Modbus RTU commands.
The SUPERtrol II then responds to these information and command requests.
Process variables and totalizers are read in register pairs in floating point format. Time and
date are read as a series of integer register values. Alarms are individually read as coils. Action
routines are initiated by writing to coils.
9.4 SUPERtrol II RS-485 Port Pinout
1
2
3
4
5
6
7
8
9
1 Ground
2 Ground
3 Ground
4 TX/RX (+)
5 TX/RX (-)
6 Do Not Use
7 Terminating Resistor (180 Ω)
8 TX/RX (+)
9 TX/RX (-)
NOTES:
4 is internally connected to 8
5 is internally connected to 9
To terminate end of cable, connect
pin 7 to either 4 or 8.
Request
SUPERtrol II RS-485
Option with Modbus RTU Protocol
manual for complete details of RS-
485
Summary of Contents for SUPERtrol II
Page 2: ......
