Modbus Communications; Warning - MSA Ultima Instruction Manual Addendum

Figure 2-4. Push-button Wiring
• ModBUS Port
• See ModBUS data table definition in this addendum.
During the calibration process, the transmitter is in
Maintenance mode, all alarming is inhibited for all sensors,
and transmitter will not alert user to potential hazardous sit-
uations.
• During the calibration of a sensor, a ModBUS request for the gas
level returns the actual value. The other sensors on that specific
transmitter are not active. A gas level of -99.9 will be returned to
indicate that.

ModBUS Communications

Baud rate and data format defaults per data table specification are
adjustable by using a:
• Hand-held Controller or
• ModBUS command.
Each transmitter:
• Is a slave on the communications network
• Must have a unique address and serial format compatible with
transmitter configuration.

" WARNING

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