5
5.6 Online Program Change for Redundancy
5.6.2 Program Change While CPU is Running
5
- 106
1
OV
ER
VIE
W
2
SYS
TEM
CONFIGURA
TI
ON
3
TR
AC
KI
N
G
C
ABL
E
4
P
R
OCE
DURE
FO
R
S
TAR
TING
UP
A
RE
DUN
DAN
T
S
Y
S
T
E
M
5
RE
DUNDA
NT S
Y
S
T
E
M
FUNCTIONS
6
RE
DUN
DAN
T
S
Y
S
T
E
M
NE
TW
O
R
K
S
7
PR
OG
R
A
MM
IN
G
CA
UTIO
N
S
8
TR
O
U
BLE
S
HOOTING
(6) Special Relays And Special Registers For Online Program Change
(a) Special Relays For Online Program change
Special relays for online program change are shownin Table5.55
(b) Special Registers For Online Program Change
Special registers for online program change are shownin Table5.56
Table5.55 Special Relays For Online Program change
Number
Name
Explanation
SM1709
Manual system switching disable/
enable setting during online
program change redundant
tracking
(1) Turning this relay from OFF to ON enables manual system switching during online
program change redundant tracking.
After the manual system switching disable status is canceled, the system
automatically turns off SM1709.
(2) System switching due to any of the following conditions is executed even during
online program change redundant tracking, regardless of the status of this relay.
• Power off, reset, hardware failure, CPU stop error
(3) In either of the following statuses, the system switching disable status can also be
canceled by this relay.
• Multiple-block online program change redundant tracking execution status
• File batch online program change redundant tracking execution status
• Online file writing redundant tracking execution status
SM1710
Transfer tracking data during
online program change enable
flag
(1) Set whether the tracking of the following data will be executed or not during online
program change redundant tracking.
• Device memory
(Including SM/SD that will automatically execute tracking)
• PID control command information, SFC information
(2) This relay can be also used to set whether tracking is to be executed or not in the
multiple-block online program change or online file writing redundant tracking
execution status.
(3) This SM is also transferred form control system CPU module to standby system
CPU module by tracking data.
Table5.56 Special Registers For Online Program Change
Number
Name
Explanation
SD1710
Waiting time for online program
change (standby system)
(1) Set in seconds the waiting time of the standby system CPU module from when
online program change to the control system CPU module is completed by the
online program change for redundancy function until the online program change
to the standby system CPU module starts.
(2) If no online program change request is issued to the standby system CPU module
within the preset time after completion of the online program change to the control
system CPU module, both system CPU modules judge it as the failure of the
online program change for redundancy. In this case, both system CPU modules
resume the consistency check between system A & B suspended during the
online program change. Also, the control system CPU module is set to accept a
new request of online program change for redundancy.
(3) When both systems are powered on, 90 seconds are set to SD1710 as the default
value.
(4) Set the value within the range 90 to 3600 seconds. When the setting is 0 to 89
seconds, it is regarded as 90 seconds for operation. If the setting is outside the
allowed range, it is regarded other than 0 to 3600 seconds for operation.
(5) The waiting time for a start of online program change to the standby system CPU
module is checked with the SD1710 setting during redundant tracking of multiple-
block online program change or online file writing.