Output Off Bit - Omron C200H Operation Manual

SR Area
Operating without a Battery
3-4-5

Output OFF Bit

Operating without a Battery
In the following cases, DM (DM 0000 to DM 0999), HR, AR, CNT, and SR
area data will not be retained in the CPU Unit's internal RAM when the power
is turned OFF.
• When a RAM Unit without battery backup is used and the backup time has
been exceeded for the backup capacitor.
• When a RAM Unit with battery backup is used, but the battery is low.
Because this data is not retained, the Output OFF Bit (SR 25215) and the I/O
Status Hold Bit (SR 25212) are not reliable when the power is turned ON. If
the Output OFF Bit is ON, the outputs from all of the Output Units will be
turned OFF. To ensure that the outputs from all of the Output Units are not
turned OFF when the power is turned ON, take a preventive measure, such
as writing the following instructions into the ladder program.
First Cycle Flag
(25315)
SR bit 25215 is turned ON to turn OFF all outputs from the PC. The OUT IN-
HIBIT indicator on the front panel of the CPU will light. When the Output OFF
Bit is OFF, all output bits will be refreshed in the usual way.
The status of the Output OFF Bit is maintained for power interruptions or
when PC operation is stopped, unless the I/O table has been registered
(CPU Units CPU01-E and CPU03-E), or the I/O table has been registered
and either the Force Status Hold Bit or the I/O Status Hold Bit has not been
enabled with SYS(49) (CPU Unit CPU11-E).
In the following cases, DM (DM 0000 to DM 0999), HR, AR, CNT, and SR
area data will not be retained in the CPU Unit's internal RAM when the power
is turned OFF.
• When a RAM Unit without battery backup is used and the backup time has
been exceeded for the backup capacitor.
• When a RAM Unit with battery backup is used, but the battery is low.
Because this data is not retained, the Output OFF Bit (SR 25215) and the I/O
Status Hold Bit (SR 25212) are not reliable when the power is turned ON. If
the Output OFF Bit is ON, the outputs from all of the Output Units will be
turned OFF. To ensure that the outputs from all of the Output Units are not
turned OFF when the power is turned ON, take a preventive measure, such
as writing the following instructions into the ladder program.
First Cycle Flag
(25315)
Section 3-4
ANDW (34)
#6FFF
252
252
ANDW (34)
#6FFF
252
252
29