3. SPECIFICATIONS
3
−
7
MELSEC-A
(5)
Slave down signal: Xn4
This signal indicates whether any slave station has stopped communication.
(a)
This signal turns ON if any slave station for which parameters are set stops
communication.
OFF : All stations communicating normally
ON
: Abnormal communication at a station
Which station has stopped communication can be confirmed from the station
communication status area at addresses 01BC
H
to 01BF
H
of the buffer memory.
(b)
This signal automatically turns OFF when the slave station communication restarts.
(6)
Parameter-being-set
: Xn6
Parameter set complete
: Xn7
Parameter set request
: Y(n+1)7
These signals are used to set parameters with a sequence program. Set the parameters
when the refreshing (Xn1) signal is OFF.
(a)
Follow the procedure below to write parameters.
1) Write the parameters to the parameter set area in buffer memory.
2) Turn on parameter set request (Y(n+1)7) with a sequence program.
(b)
Once the write request is received and the parameter analysis completes normally,
parameter-writing action gets executed with the parameter-being-set (Xn6) turned
ON.
(c)
Parameter set complete (Xn7) automatically turns ON when the parameter write
operation is complete. Communication with other slave stations is disabled while
parameters are being set.
Parameter set complete (Xn7) automatically turns OFF when parameter set request
(Y(n+1)7) turns OFF.
POINTS
(1) If refreshing (Xn1) is ON when parameter set request (Y(n+1)7) turns ON,
parameter set complete (Xn7) does not turn ON. First, turn OFF refresh request
(Y(n+1)1) and confirm that refreshing (Xn1) is OFF before turning parameter set
request (Y(n+1)7) OFF and back ON.
(2) If parameter set request (Y(n+1)7) is ON when refresh request (Y(n+1)1) turns ON,
refreshing (Xn1) does not turn ON. First, turn OFF parameter set request
(Y(n+1)7), then reset refresh request (Y(n+1)1) and turn it back ON.
Refresh request (Y(n+1)1)
Refreshing (Xn1)
Parameter set request (Y(n+1)7)
Parameter set complete (Xn7)
TO instruction
Write parameter
data
Parameter being set (Xn6)