CONTREX CX-1200 - Manual (Page 274)

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CX-1200 Serial Communications Binary Data-Link Protocol
(Message Transmission / Response Structures)
STX BYTE
Length BYTE
Address BYTE
Function BYTE
Message Error BYTE
Data Field Defined later for each function type
ETX BYTE
CRC WORD (2 BYTES)
Valid Binary Protocol Functions:
1) Data Read Single Parameter
2) Data Write Single Parameter
3) Data Read Parameter Block (Limit 16)
4) Data Write Parameter Block (Limit 16)
5) Control Commands
6) PLC Program Download from Control
7) PLC Program Upload to Control
8) Custom Engineering Units Download
9) Custom Engineering Units Upload
10) Data Read Constant Table (Limit 6)
11) Parameter Data Trace Enable/Disable (enables/disables the CX-1200's ability to collect data
traces)
12) Data Read Parameter Trace (read consecutive trace data from the CX-1200)
13) Data Read Trace Status Byte
Example:
Request for CP-210
Table 38 Data Read Single Parameter, Host Transmission
STX LEN ADDR FUNC DATA ETX CRC
02 09 01 01 00D2 03 0C56