(2) Communication procedure and format
Initiative of the sequence is on the host computer side. The sequence always starts with
the host computer side and the counter responds to it. The host computer side has the
initial transmission right, and the counter always give a response back to the host
computer when a command is transmitted from the host computer to the counter.
However, the counter does not respond when counter unit No. specified is different or
when parity error or check sum error occurs.
Command
Block
#
Unit No.
Command code
Command data
Check sum
CR
Response
Block
#
Unit No.
Command code
Response data
Status
Check sum
CR
When data out of the setting range is coming in at setting by communication, setting is not
conducted, instead response block (EE command) containing error code is sent back.
The values set in setting mode by communication are stored in E
2
ROM. Since E
2
ROM
has the life of 1,000,000 times, avoid unintentional continuous storing of the set values.
The values set in counter mode are not stored in E
2
ROM.
(3) Check sum procedure
Operation range
: from # to the last letter of command data
Operation procedure : Add all ASCII code in operation range and take a lower 1 byte.
Add 30H to the 1 byte.
Example: #
0
0
V R
23H 30H 30H 56H 52H
23H + 30H + 30H + 56H + 52H = 12BH
Take 2B and add 30H to each part of the 1 byte. Check sums are 32H and 3BH.
Therefore, command block will be:
#
0
0 V R 2 ; [CR]
23H 30H 30H 56H 52H 32H 3BH 0DH
Note: ASCII code and check sum data
Check sum data are not the letter data of the ASCII code, but correspondence will
be as the table below.
Letter data
0
･･･
9
A B C D E F
ASCII
30H
･･･
39H 41H 42H 43H 44H 45H 46H
Check sum
30H
･･･
39H 3AH 3BH 3CH 3DH 3EH 3FH
－
２８
－
