Sr Area; Battery Alarm Flag; Scan Time Error Flag; High-Speed Drum Counter Reset - Omron SYSMAC C20P Operation Manual

SR Area

3–4

SR Area

3–4–1

Battery Alarm Flag

3–4–2

Scan Time Error Flag

3–4–3

High-speed Drum Counter Reset

3–4–4

Clock Pulse Bits

24
The SR area contains flags and control bits used for monitoring system op-
eration, accessing clock pulses, and signalling errors. SR area word ad-
dresses range from 18 through 19; bit addresses, from 1808 through 1907.
The following table lists the functions of SR area flags and control bits. Most
of these bits are described in more detail following the table.
Unless otherwise stated, flags are OFF until the specified condition arises,
when they are turned ON. Bits 1903 to 1907 are turned OFF when END is
executed at the end of each program scan, and thus cannot be monitored on
the Programming Console. Other control bits are OFF until set by the user.
Word Bit
18 08
09
10
11
12
13
14
15
19 00
01
02
03
04
05
06
07
SR 1808 turns ON if the voltage of the CPU backup battery drops. A voltage
drop can be indicated by connecting the output of this bit to an external indi-
cating device such as a LED. This bit can be used in programming to activate
an external warning for a low battery.
SR 1809 turns ON if the scan time exceeds 100 ms. This bit is turned ON
when the scan time is between 100 and 130 ms. The PC will still operate but
timing may become inaccurate. The PC will stop operating if the execution
time exceeds 130 ms.
SR 1810 turns ON for one scan time when the hard reset signal (input 0001)
is turned ON.
Three clock pulses are available to control program timing. Each clock pulse
bit is ON for the first half of the rated pulse time, then OFF for the second
half. In other words, each clock pulse has a duty factor of 1 to 1.
Function

Battery Alarm Flag

Scan Time Error Flag

High-speed Counter Reset
Always OFF Flag
Always OFF Flag
Always ON Flag
Always OFF Flag
First Scan Flag
0.1-second Clock Pulse
0.2-second Clock Pulse
1-second Clock Pulse
Error (ER) Flag
Carry (CY) Flag
Greater Than (GR) Flag
Equals (EQ) Flag
Less Than (LE) Flag
Section 3–4