- 26 -
6.10 Explanation about ASCII Codes
■ The following codes from
(a) Start Code, (b) Slave Address, up to (j) Error Type will be expressed in
ASCII code:
■ See "10. List of ASCII Codes" for the detail
s about ASCII codes.
■ To convert into ASCII code, see the message structure in 6.8 and 6
.9.
a) Start Code
It is a code that is necessary for the receiving side to detect the start of the message. It shall
be attached to the start of the character string to be sent.
b) Slave Address
It is an address of the device that will be communicated by the upper computer (this product).
The address in the response message from this product indicates the source of the response message.
c) Function Code
Enter the code 03H or 10H.
03H: If the data is to be read from this product
10H: If the data is to be written or saved into this product
d) Number of Registers
It specifies the number of registers that write. Since the number of registers of this product
is fixed to 2, set it to "0002H."
e) Register Address
It specifies the position of data to be read or written with two bytes.
See "10. List of Identifiers (Codes)" for the address of each command.
f) LRC
It is an error checking code for the detection of the possible error in the message. It sends LRC.
LRC that is used in this product is a value where all data in the message, except for start code
and end code, are summed up without performing a carryover and treat the sum total as the complement
of 2.
Any portion that is expressed as "1" and "B" shall be considered as "1BH."
See "6.12 Sample Computation of LRC" for the computation method of LRC.
If 12H was computed as an error code, attach "1" and "2" at the end of the message.
g) End Code
It is a code that is necessary for the receiving side to detect the end of the message. CR(0DH)
and LF(0AH) shall be attached at the end of the character string to be sent.
h) Number of Bytes
It specifies the number of registers that read and write x 2. Since the number of registers of
this product is 2 (fixed), set "04H."
