Omron V670 Series, User Manual

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5-2 Command Response Format
5-5
(4) Available designation range of first address and number of bytes
A command to specify the first address and the number of bytes in a command and the available designation range are shown in the
table below. If you specify any value out of the available range, a command error occurs.
* If the first address is 20h and the number of bytes is 70h, a command error occurs due to "A + B = 90h".
(5) Example of calculation of FCS
Exclusive-OR is executed from the node number to the end of data at every 1 byte. The result is converted into an ASCII code and
added.
Reading 16 bytes from the address 0000h
Command code Available designation range of first address and number of bytes Other restriction
Read (RD) A) Available designation range of first address: 0000h to 007Fh
B) Available designation range of number of bytes: 01h to 80h A + B ≤ 80h*
Write (WT) A) Available designation range of first address: 0000h to 007Fh
B) Available designation range of number of bytes: 01h to 80h A + B ≤ 80h*
Computation Write
(CW) A) Available designation range of first address: 0000h to 007Fh
B) Available designation range of computation area: 01h to 80h A + B
≤
80h*
Data Fill (DF) A) Available designation range of first address: 0000h to 007Fh
B) Available designation range of end address: 0000h to 007Fh A
≤
B
Memory Check (MD) A) Available designation range of first address: 0000h to 007Dh
B) Available designation range of number of check bytes: 03h to 80h A + B
≤
80h*
Command code Terminator
Data
Node No.
Calculation range of FCS
Calculation result
7 9