Bender COMTRAXX COM465IP - Page 43

Modbus TCP server
43
COM465IP-COM465DP_D00216_02_M_XXEN/03.2017
Example:
Channel 2 of the device with address 3 is to be queried. How is the start address determined to send
the query for the channel? In our example, the relevant cells in the table are marked in bold.
1. For device address 3 the first part of the address, 0x03 (high byte), is taken from table 6.1.
2. For channel 2 the second part of the address, 0x14 (low byte), is taken from table 6.2. For the
number of words to be requested the number 4 is taken from the same table:
(0x14 to 0x17 = 0x04).
3. The start address 0x0314 is formed from the high byte and low byte.
Tab. 6.2: Modbus address assignment of the channels in a device;
Hex representation: horizontal = units, vertical = sixteens
Abbreviations for memory contents:
C = Common alarm
D = Device lost (device failure)
R. = Reserved
A detailed description of the data formats for the device type, timestamp etc. is given below.
Memory image of a device
LoByte
0123456789ABCDEF
0x00 --------------------------- Device type ---------------------------- ------ Time stamp ------ C D R.
0x10 Channel 1 Channel 2 Channel 3 Channel 4
0x20 Channel 5 Channel 6 Channel 7 Channel 8
0x30 Channel 9 Channel 10 Channel 11 Channel 12
0x40 Channel 13 Channel 14 Channel 15 Channel 16
0x50 Channel 17 Channel 18 Channel 19 Channel 20
0x60 Channel 21 Channel 22 Channel 23 Channel 24
0x70 Channel 25 Channel 26 Channel 27 Channel 28
0x80 Channel 29 Channel 30 Channel 31 Channel 32
0x90 3334353637383940414243444546474849505152535455565758596061626364
0xA0 R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.
0xB0 R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.
0xC0 R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.
0xD0 R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.
0xE0 R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.
0xF0 R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.R.