Analog And Digital Communications; Figure 11 Rs458 & Analog Output Connector - Michell Instruments Optidew User Manual

Optidew User's Manual
Fuse
This product is provided with an externally mounted fuse located next to the power connector.
The fuse is rated at 5 x 20mm medium acting: T 2.5 A H 250V.
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.

2.4.2. 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.
2.4.2.1. Digital Communications
From left to right, the first four pins of this connector are used for RS485 communications.
Figure 11 RS458 & Analog output connector
Pin Label
GND
RS485 B
RS485 A
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.
Application software is available and can be used to communicate with the instrument. Refer to
the Application Software section at the end of the manual.
10
Description
Ground
RS485 Data B
RS485 Data A
Ground
97551 Issue 4.1, October 2019