Omron CQM1H-CLK21 - Manual (Page 200)

177
Introduction Section 6-1
using the message service, it is advisable to prevent this situation from oc-
curring by performing resend processing at the node where instructions
are issued. With the SEND, RECV, and CMND instructions, resend pro-
cessing is performed automatically once the number of retries has been
set, so be sure to specify a number other than “0” for the number of retries.
Indirect Designation of
Beginning Words CVM1, CV-series, and CS/CJ-series PLCs have a larger area than CQM1H-
series PLCs, so the beginning words for sending and receiving at destination
nodes cannot always be directly specified by means of SEND and RECV
operands. Moreover, depending on circumstances, it may be desirable to
change the beginning word at destination nodes.
In such cases, set the “Direct/Indirect” control data designation to “1” (Indi-
rect), and specify the beginning words for sending and receiving as described
below.
SEND
The beginning receive word is determined by the contents of the destination
node’s D and D+1 words.
RECV
The beginning send word is determined by the contents of the destination
node’s S and S+1 words.
S: Source node beginning send word
D: Destination node beginning receive word
C: Source node first control data word
@SEND(90)
S
D
C
D
D+1
0 0 0 0
15141312 1110 9 8 7 6 5 4 3 2 1 0
Area code* Word address (5th digit)
Word address (1st digit)
Word address (2nd digit)
Word address (3rd digit)
Word address (4th digit)
S: Source node beginning send word
D: Destination node beginning receive word
C: Source node first control data word
@RECV(98)
S
D
C
S
S+1
0 0 0 0
151413121110 9 8 7 6 5 4 3 2 1 0
Area code* Word address (5th digit)
Word address (1st digit)
Word address (2nd digit)
Word address (3rd digit)
Word address (4th digit)