Duplex Initialization - Omron SYSMAC CVM1 Series Operation Manual

Cycle Time
6-2-3 Switching from Duplex to Simplex Operation
CPU Status
Active CPU → Standby CPU,
Standby CPU → Active CPU
Active CPU remains active
The configuration of the PC can greatly affect the cycle time. The following table
shows how duplex initialization will increase the cycle time for a PC configuration
with a normal cycle time of 20 ms.
Number of EM banks
0
2
4
8
The maximum cycle time (T ms) can be calculated with the following equation:
T = (UM size (KW) × 1.22) + (EM banks × 78.0) + normal cycle time
Note 1. The standby CPU's WAIT indicator will be lit and its DPL RUN indicator will
be flashing during duplex initialization.
2. If the standby CPU's Usage Switch is set to "NO USE" during duplex initiali-
zation, the CPU's program and PC Setup will be incorrect and the CPU will
not operate properly when it is started.
During duplex operation, the active CPU and standby CPU monitor the other
CPU's errors. Also, the synchronous transmission buses are also monitored
since it is a duplex system and the PC will switch from duplex operation to sim-
plex operation when an error is detected.
The following table lists the cases in which operation will be switched from du-
plex to simplex operation.
Cause for Switching
The active and standby CPU Units will be
interchanged in the following cases:
S Memory error
S CPU error
S Active CPU's Usage Switch setting
changed from "USE" to "NO USE."
The active CPU Unit will remain active in
the following cases:
S Duplex bus error
S Duplex verification error
S A memory error or CPU error occurs in
the standby CPU.
S Standby CPU's Usage Switch setting
changed from "USE" to "NO USE."
S Memory or CPU errors occur in both
the active and standby CPUs.
S The DPL Unit's Mode Switch setting is
set to "SPL" and its Initialize Button is
pressed.
Program size Maximum cycle time
Minimum 127 ms
Maximum 200.2 ms
Minimum 283 ms
Maximum 356.2 ms
Minimum 439 ms
Maximum 512.2 ms
Minimum 751 ms
Maximum 824.2 ms
Precautions during Switching
Commands issued from Programming
Devices or host computers may be
corrupted whether the device is connected
to the PC through the Programming Device
Connector, Host Link Connector, or the
Programming Device Connector on an I/O
Interface Unit.
A communications error may occur in a
Programming Device. Program a host
computer to retry failed transmissions.
The execution conditions for
up-differentiated (j) variations of
SEND(192), RECV(193), CMND(194), and
IORF(184) might not be recognized.
The cycle time will be shortened.
The active CPU will continue operating.
The cycle time will be shortened.
Section 6-2
421