DM240XR High-Speed Digital Modulator
User Interfaces
MN-DM240XR– Revision 12
4–33
Table 4-4. Checksum Calculation Example
BYTE FIELD
DATA CONTENT
RUNNING CHECKSUM
<BYTE COUNT> (Byte 1)
00h = 00000000b
00000000b
<BYTE COUNT> (Byte 2)
02h = 00000010b
00000010b
<SOURCEID>
F0h = 11110000b
11110010b
<DESTINATION ID>
2Ah = 00101010b
00011100b
<FSN>
09h = 00001001b
00100101b
<OPCODE> (Byte 1)
00h = 00000000b
00101000b
<OPCODE> (Byte 2)
03h = 00000011b
00101000b
<DATA> (Byte 1)
DFh = 11011111b
00000111b
<DATA> (Byte 2)
FEh = 11111110b
00000101b
Thus, the checksum is 00000101b; which is 05h or 5 decimal. Alternative methods of
calculating the checksum for the same message frame are:
00h + 02h + F0h + 2Ah + 09h + 00h + 03h + DFh + FEh = 305h.
Since the only concern is the modulo 256 (modulo 100h) equivalent (values that can be
represented by a single 8-bit byte), the checksum is 05h.
For a decimal checksum calculation, the equivalent values for each information field are:
0 + 2 + 240 + 42 + 9 + 0 + 3 + 223 + 254 = 773;
773/256 = 3 with a remainder of 5. This remainder is the checksum for the frame.
5 (decimal) = 05h = 0101b = <CHECKSUM>
Summary of Contents for Radyne DM240XR
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Page 23: ...Errata C for MN DM240XR Rev 12 ER DM240XR EC12 Blank Page ...
Page 34: ...Table of Contents Revision 12 DM240XR High Speed Digital Modulator MN DM240XR viii Notes ...
Page 46: ...DM240XR High Speed Digital Modulator Installation MN DM240XR Revision 12 2 4 Notes ...
Page 96: ...DM240XR High Speed Digital Modulator User Interfaces MN DM240XR Revision 12 4 48 Notes ...
Page 200: ...DM240XR High Speed Digital Modulator TCP IP Ethernet Setup MN DM240XR Revision 12 B 8 Notes ...
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