IDEC FC6A-C16K1CE Communications Manual page 89

Delimiter
A delimiter for the data register in the receive format can be assigned. Using a delimiter, incoming data of variable length can be
received and stored to data registers.
Delimiter
The incoming data is stored to data registers until all the data specified with receive digits, conversion type, and repeat
Designated
is processed or the specified delimiter is received.
The incoming data is stored to data registers until all the data specified with receive digits, conversion type, and repeat
No delimiter
is processed.
Note: Delimiters for data registers can be used in the receive format of RXD instructions only.
Designating Constant as Start Delimiter
A start delimiter can be programmed at the first byte in the receive format of a RXD instruction; the FC6A Series MicroSmart will
recognize the beginning of valid communication, although a RXD instruction without a start delimiter can also be executed.
When a constant value is designated at the first byte of source device S1, the one-byte data serves as a start delimiter to start the
processing of the received data.
A maximum of five instructions each of RXD1 through RXD3 with different start delimiters can be executed at the same time.
When the first byte of the incoming data matches the start delimiter of a RXD instruction, the received data is processed and
stored according to the receive format specified in the RXD instruction. If the first byte of the incoming data does not match the
start delimiter of any RXD instruction that is executed, the FC6A Series MicroSmart discards the incoming data and waits for the
next communication.
When a RXD instruction without a start delimiter is executed, any incoming data is processed continuously according to the receive
format. Only one instruction each of RXD1 through RXD3 without a start delimiter can be executed at a time. If start inputs to two
or more RXD instructions without a start delimiter are turned on simultaneously, the one at the smallest address is executed and
the corresponding completion output is turned on.
Example:
(1) When a RXD instruction without a start delimiter is executed
Incoming Data
"0" "1" "2"
(30h) (31h) (32h)
1st
character
The incoming data is divided, converted, and stored to data registers according to the receive format.
(2) When RXD instructions with start delimiters STX (02h) and ENQ (05h) are executed
Incoming Data
STX "1" "2"
(02h) (31h) (32h)
ENQ "A" "B"
(05h) (41h) (42h)
RXD Instruction 1
STX (02h)
Compare
RXD Instruction 2
ENQ (05h)
The incoming data is divided, converted, and stored to data registers according to the receive format.
Start delimiters are not stored to data registers.
How the incoming data is stored to data registers
When D100 is designated as the first data register
"3"
(33h)
"3"
(33h)
"C"
(43h)
When D100 is designated as the first data register
When D200 is designated as the first data register
FC6A S M S A
ERIES ICRO MART LL
5: U
- -O T C
IN NE YPE OMMUNICATION
C
SER OMMUNICATION
**** h
D100
D101 **** h
D100+n **** h
**** h
D100
D101 **** h
D100+n **** h
D200 **** h
D201 **** h
**** h
D200+n
M FC9Y-B1730
ANUAL
I
NSTRUCTIONS
5-13