Data Format Structure; Command Frame - Omron E5ZN Operation Manual

Data Format Structure

5-2

Data Format Structure

5-2-1

Command Frame

Communications conforming to the CompoWay/F serial communications pro-
tocol involve transmission of blocks of data called frames. Those sent from
the host PC are command frames and those sent from the Temperature Con-
troller are response frames. The structure of these frames is shown below.
In the following frame description, the suffix H added to a numeric value, as in
02H, means the value is a hexadecimal number. And quotation marks around
an alphanumeric value, as in "00," mean that the value is an ASCII character
set. The number underneath each delimiter in a frame indicates the number of
bytes.
Node No.
STX
02H
1 2
STX
Node No.
Sub-address
SID (Service ID)
FINS-mini
command text
ETX
BCC
STX Node No.
02H 30H 30H 30H 30H 30H 30H 35H 30H 30H
BCC = 30H Å 30H Å 30H Å 30H Å 30H Å 30H Å 35H Å 30H Å 30H Å 03H = 36H
Å : XOR (exclusive OR) operation
Note How to Determine the BCC:
The BCC is determined by XOR operation on a byte-by-byte basis of the values within
the range from the node number field to the ETX field. The result (36H in the example
shown above) is placed in the BCC field.
FINS-mini
Sub-
SID
command text
address
"00" "0"
2 1
BCC calculation range
Code indicating the start of a command frame (02H). Be sure to
place this code in the first byte of a command frame.
Node ID specifying the destination of a command frame. Set this
No. to the unit number of the Temperature Controller.
If you want to broadcast a command, set the node number to
"XX." No response is given from the Temperature Controllers for
broadcast commands.
Not used for E5ZN. Always set the sub-address to "00."
Not used for E5ZN. Always set the SID to "0."
Command text
Code indicating the end of text (03H)
Block Check Character
The result of a block check on the BCC calculation range is
stored in this field.
Sub- FINS-mini
SID
command text
address
Section 5-2
ETX BCC
03H
1 1 byte
ETX BCC
03H 36H
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