Thermo Scientific 5028i, Instruction Manual

Page: 305 / 330

Thermo Fisher Scientific Model 5028
i
Instruction Manual C-1
Appendix C
MODBUS Protocol
This appendix provides a description of the MODBUS Protocol
Interface and is supported both over RS-232/485 (RTU protocol) as
well as TCP/IP over Ethernet.
The MODBUS commands that are implemented are explained in
detail in this document. The MODBUS protocol support for the
iSeries enables the user to perform the functions of reading the various
concentrations and other measurement values, read the status of the
digital outputs of the analyzer, and to trigger or simulate the activation
of a digital input to the instrument. This is achieved by using the
supported MODBUS parameters listed below.
Up to three simultaneous connections are supported over Ethernet.
For details of the Model 5028
i MODBUS Protocol specification, see
the following topics:
l
“ Serial Communication Parameters ” on page C-1
l
“ TCP Communication Parameters ” on page C-2
l
“ Application Data Unit Definition ” on page C-2
l
“ Function Codes ” on page C-3
l
“ MODBUS Parameters Supported ” on page C-8
Additional information on the MODBUS protocol can be obtained at
http://www.modbus.org . References are from MODBUS Application
Protocol Specification V1.1a MODBUS-IDA June 4, 2004.
The following are the communication parameters that are used to
configure the serial port of the iSeries to support MODBUS RTU
protocol.
Number of Data bits
: 7 or 8
Number of Stop bits : 1 or 2
Parity : None, Odd, or Even
Data rate : 1200 to 115200 Baud (9600 is default)
Serial Communication
Parameters