Table of Contents
Advertisement
6.3 Latch Function
(1) Definition
Data in each device of the CPU module is cleared and set back to its default (bit device: off, word
device: 0) when;
• the CPU module is powered off and then on,
• the CPU module is reset, or
• power failure occurs exceeding the allowable momentary power failure time.
This function holds the device data when any of the above events occur.
(2) Program operation when the latch function is used
Program operation is the same, regardless of the latch status
(3) Application
This function is used to hold the data managed by sequential control and continue control operation
even when the CPU module is powered off and then on, the CPU module is reset, or power failure
occurs exceeding the allowable momentary power failure time.
(4) Devices that can be latched
The following devices can be latched
• Latch relay (L)
• Link relay (B)
• Annunciator (F)
• Edge relay (V)
• Timer (T)
• Retentive timer (ST)
• Counter (C)
• Data register (D)
• Link register (W)
When the battery life-prolonging function (
latched.
.
(By default, only the latch relay is enabled for latch.)
.
Section 6.26) is set, the latch relay cannot be
CHAPTER6 FUNCTIONS
6 - 7
1
2
3
4
5
6
7
8
Advertisement
Table of Contents
