Analog And Digital Communications; 2.3.2.1 Digital Communications; Figure 10 Rs485 & Analog Output Connector - Michell Instruments Optidew User Manual

Optidew User's Manual
Mains 230 V AC 2.5 AH 250 V
A replacement fuse can be obtained by contacting Michell Instruments Service
Department.
Equipment Ratings
This product is designed to be safe at least under the following conditions: between
a temperature range of -40 to +60°C (-40 to +148°F), in maximum 80% relative
humidity for temperatures up to +31°C (+88°F) decreasing linearly to 50% RH at
+50°C (+122°F). Overvoltage Category II. Pollution Degree 2. Altitudes up to 2000m.
Indoor use only but is IP65 rated.
See Appendix A, Technical Specification, for full operating parameters.
2.3.2

Analog and Digital Communications

Note: When using screened cable, the screen should only be connected to a ground
point at either the Optidew installation side, or at the receiving equipment. Failure to
observe this precaution can result in ground loops and equipment malfunction.

2.3.2.1 Digital Communications

The leftmost four pins of this connector are used for RS485 communications.
Pin Label
GND
RS485 A
RS485 B
GND
The Optidew provides Modbus RTU over RS485 or USB (Bench Top only). An Ethernet
module is optionally available for both instruments, and provides Modbus TCP
communication.
The Modbus register map can be found in Appendix B.
The application software provided can be used to communicate with the instrument.
Refer to the Application Software section at the end of the manual.
Michell Instruments
RS485 & analog output connector
Figure 10
Ground
RS485 Data A
RS485 Data B
Ground
INSTALLATION
Description
9