Appendix 3 Modbus® Table And Operations - RC Systems ViewSmart 1600+ Operation Manual

Appendix 3 Modbus® Table and Operations
The ViewSmart 1600+ is equipped with two standard programmable Modbus® RS-485 Master/Slave ports,
and has the ability to add two addition isolated Modbus® RS-485 Master/Slave ports (base 1).
The Modbus® slave ports allow function code 5 (write coil), as well as function code 6, and 16 (write
holding registers). By default, all Modbus® writes are disabled except the unlock parameter 40099. The
Modbus® lock code can be written to register 40099 to enable writes to other registers. The unit will be
unlocked for 10 minutes after the last write occurs. After the 10 minute timeout, the unit will
automatically save any parameters that have been written. All written parameters can be saved manually
by writing a value of 1 to coil 95 or register 40095.These function codes can be used to write configuration
parameters to the ViewSmart 1600+. Writing parameters that span multiple register (such as 32bit
floating points) requires function code 16. All registers must be written at once.
The following table describes the ViewSmart 1600+ Modbus® slave database. Any portion of this data may
be read by a Modbus® master device such as a PC, PLC or DCS. Since the Modbus® port is RS-485, multiple
ViewSmart 1600+ controllers may be multi-dropped onto the same cable.
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Revision B 89