Gocator Line Profile Sensors: User Manual
Protocols • 663
Selcom Protocol
This section describes the Selcom serial protocol settings and message formats supported by Gocator
sensors.
Gocator 2500 series sensors do not support the Selcom Serial Protocol.
To use the Selcom protocol, it must be enabled and configured in the active job.
For information on configuring the protocol using the Web interface, see Serial Output on page 443.
Units for data scales use the standard units(mm, mm
2
, mm
3
, and degrees).
Serial Communication
Data communication is synchronous using two unidirectional (output only) RS-485 serial channels: data
(Serial_Out0) and clock (Serial_Out1). See Serial Output on page 771 for cable pinout information.
Measurement results are sent on the serial output (data)in asynchronous mode. Measurement values
and decisions can be transmitted to an RS-485 receiver, but job handling and control operations must be
performed through the Gocator's web interface or through communications on the Ethernet output.
Connection Settings
The Selcom protocol uses the following connection settings:
Parameter Value
Data Bits 16
Baud Rate (b/s) 96000, 512000, 1024000
Format Binary
Serial Connection Settings
Message Format
The data channel is valid on the rising edge of the clock and data is output with the most significant bit
first, followed by control bits for a total of 16 bits of information per frame. The time between the start
of the camera exposure and the delivery of the corresponding range data is fixed to a deterministic
value.
The sensor can output data using one of four formats, illustrated below, where:
l MSB = most significant bit
l LSB = least significant bit
l C = data valid bit (high = invalid)
l S= whether data is acquired in search mode or track mode (high = search mode)