Omron E5ZN - Data Format Structure; Command Frame

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Data Format Structure Section 5-2
5-2 Data Format Structure
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.
5-2-1 Command Frame
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.
STX Code indicating the start of a command frame (02H). Be sure to
place this code in the first byte of a command frame.
Node No. 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.
Sub-address Not used for E5ZN. Always set the sub-address to “00.”
SID (Service ID) Not used for E5ZN. Always set the SID to “0.”
FINS-mini
command text
Command text
ETX Code indicating the end of text (03H)
BCC Block Check Character
The result of a block check on the BCC calculation range is
stored in this field.
02H “00” “0” 03H
11 122 1 byte
Sub-
address
SID
FINS-mini
command text
ETX BCC
BCC calculation range
STX
Node No.
STX Node No.
Sub-
address
SID
FINS-mini
command text
ETX BCC
02H 03H30H 30H 30H 30H 30H 30H 35H 30H 30H 36H
BCC = 30H
⊕ 30H ⊕ 30H ⊕ 30H ⊕ 30H ⊕ 30H ⊕ 35H ⊕ 30H ⊕ 30H ⊕ 03H = 36H
⊕: XOR (exclusive OR) operation