30
These clock pulse bits are often used with counter instructions to create tim-
ers. Refer to
5-11 Timer and Counter Instructions
for an example of this.
Pulse width
1 min
0.02 s
0.1 s
0.2 s
1.0 s
Bit
25400
25401
25500
25501
25502
Bit 25400
1-min clock pulse
Bit 25401
0.02-s clock pulse
Bit 25500
0.1-s clock pulse
Bit 25501
0.2-s clock pulse
Bit 25502
1.0-s clock pulse
Caution
:
Because the 0.1-second and
0.02-second clock pulse bits have ON
times of 50 and 10 ms, respectively,
the CPU may not be able to accu-
rately read the pulses if program
execution time is too long.
0.1 s
.05 s
.05 s
1.0 s
0.5 s
0.5 s
0.2 s
0.1 s
0.1 s
1 min.
30 s
30 s
.02 s
.01 s
.01 s
!
3-4-10
Step Flag
SR bit 25407 turns ON for one cycle when step execution is started with the
STEP(08) instruction.
3-4-11
Duplex System Flags
Five flags are provided in the SR area to monitor Duplex System operation.
These flags are used only with a C2000H Duplex System. The following table
summarizes Duplex System flags.
Name
Bit
Function
Bus Error Flag
25408
Turns ON when an error occurs in communications
between the CPUs. When this flag turns ON, one of
the CPUs will take over control and switch to
simplex operation.
Replacement
Enabled Flag
25409
Turns ON when the other CPU may be removed.
CPU Error Flag
25410
Turns ON when a CPU error has occurred in the
other CPU.
Memory Error
Flag
25411
Turns ON when a memory error has occurred in the
other CPU.
Run Flag
25412
Stays ON during normal duplex operation.
3-4-12
Instruction Execution Error Flag, ER
SR bit 25503 turns ON if an attempt is made to execute an instruction with
incorrect operand data. Common causes of an instruction error are non-BCD
operand data when BCD data is required, or an indirectly addressed DM
SR Area
Section 3-4
