Latched Areas In The Device Range; Functions Of Devices - Delta Electronics AH500 Operation Manual

PLC action
(All latched areas are cleared.)
Default value

5.1.4 Latched Areas in the Device Range

Device Function
Input relay
X
Output relay
Y
Auxiliary relay
M*
Special auxiliary relay
SM
Stepping relay
S
Timer
T*
Counter
C*
32-bit counter
HC*
Data register
D*
Special data register
SR
Link register
L
Index register
E
*: * indicates that users can set the range of latched areas, and that the device can be set to Non-latched Area.
The range of latched areas can not exceed the device range. Above all, only 32768 data registers at most
can be non-latched areas. For example, users can set D50~D32817 or D32768~D65535 to Latched Areas
although the default range of latched areas is D0~D32767.

5.2 Functions of Devices

Procedure for processing the program in the PLC:
Input ter minal X
Regener ating the input signal
D evice memory
Proc es s in g th e prog ram
Device memory
R egener ating the output s ignal
and sending it to the output ter minal
Device type Non-latched
area
0
All devices are non-latched.
All devices are non-latched.
The default range is M0~M8191.
Some devices are latched, and cannot be changed.
Please refer to the list of special auxiliary relays for more information.
All devices are non-latched.
The default range is T0~T2047.
The default range is C0~C2047.
The default range is HC0~HC63.
AH500-EN/RS2: The default range is D0~D16383.
AH501-EN/RS2: The default range is D0~D24575.
The default range is D0~D32767.
At most 32768 devices can be latched areas.
Some are latched, and can not be changed.
Please refer to the list of special data registers for more information.
All devices are non-latched.
All devices are non-latched.
Regenerating the input signal

1. Before the program is executed, the state of the
external input signal is read into the memory of the
input signal.
2. When program is executed, the state in the memory of
the input signal does not change even if the input
signal changes from ON to OFF or from OFF to ON.
Not until the next scan begins will the input signal be
refreshed.
Processing the program

After the input signal is refreshed, the instructions in the
program are executed in order from the start address of the
program, and the results are stored in the device
memories.
Regenerating the state of the output

After the instruction END is executed, the state in the
device memory is sent to the specified output terminal.
C h a p t e r 5 D e v i c e
Latched
Output relay
area
0 0
Latched area
5 - 5