Installation
Micron Modem
0630-SOM-00001, Issue: 03
10
© Tritech International Ltd.
3.4. Communication Protocol
The Micron Modem is supplied with two communications ports labelled
MAIN
and
AUX
. All
communication to the control computer on the surface should be via the
MAIN
port, while
the
AUX
port is used for daisy chained communication links to other
Tritech International Ltd
sensors, such as the Micron Echosounder.
The communication protocols (RS232/RS485) used by the ports are factory set and are not
user selectable other than at the time of build.
The communication configuration of the modems are factory set although they can be
changed in software see Appendix A,
Changing Modem Modes (Responder/Transponder/
). The factory setting is written on the label attached to the Micron, and can also be
obtained from the original build record.
MAIN
AUX
Label Example
RS485
RS485
RS232
RS485
RS485
RS232
RS232
RS232
MODEM
750m
07619.XXXXXX
Note
If the settings are changed through software it is important to keep a record of
the changes, otherwise it can be difficult to re-connect to the modem.
• The RS232 telemetry is bi-directional, 3-wire (TX, RX and ground) between the data
modem and the controlling serial port.
• The RS485 telemetry is half-duplex, 2-wire (RS485+ and RS485-). Typically the controlling
RS485 connection can be an RS485 serial port installed in a computer or can be an RS485
to RS232/USB signal converter. The RS485 circuit inside the Micron Modem is factory
supplied with a 150Ω termination.
A pair of Micron Data Modems can be connected between two serial devices in order to
transfer data between them acoustically.
For pin-out and cable specification refer to Chapter 2,
3.5. Configuration
When installing the unit it is important to know which device is the Surface Modem (or Master)
and which is the Subsea Modem (or Slave). The product label on the underside of the unit
will identify the unit as appropriate.
