Appendix D. Communication Example - DekTec DTM-3200 User Manual

DTM-3200 – OEM Ethernet TSoIP Converter
User Manual

Appendix D. Communication Example

In the examples below, grey areas in the timing diagrams are sent by the DTM-3200, while white
areas are sent by the master. The address of the DTM-3200 in these examples is 0x12.
Write command on RS-XXX serial interface
Figure 9 shows the write command of the FEC-enable at the receive channel settings (ca
0x81, setting 4, index 0). All values are displayed as ASCII characters.
The command consists of the following parts:
 Start character 'STX'
 Two hexadecimal address characters ("12")
 Two hexadecimal category characters ("81")
 Two hexadecimal setting characters ("04")
 A write character 'W'
 Four hexadecimal index characters ("0000")
 Two hexadecimal characters ("01")
 Two hexadecimal checksum characters ("58", See Table 1)
 Stop character 'ETX'
Figure 9: Write FEC enable in the receive channel settings
Table 1: Checksum computation
Characters
STX
1
2
8
1
0
4
W
0
0
0
0
0
1
5
8
ETX
Sum:
Checksum:
ASCII value
0x02
0x31
0x32
0x38
0x31
0x30
0x34
0x57
0x30
0x30
0x30
0x30
0x30
0x31
0x35
0x38
0x03
0x2A8
0x58
41