Delta AH500 - Explanation of Redundant Instructions

Chapter 6 Applied Instructions
6-549
6.26.2 Explanation of Redundant Instructions
API Instruction code Operand Function
2900 SSO P D
Switching from Master CPU to
Standby CPU
Device X Y M S T C HC D L SM SR E K 16# “$” DF
D
       
Pulse instruction
16-bit instruction (7 steps)
32-bit
AH500
AH500
-
Symbol:
D
：
Error code Word
Explanation:
1. This instruction is for Redundant CPU Module AHCPU560-EN2.
2. When the instruction is executed, the system switches from Master CPU to Standby CPU.
3. Generally, the pulse instruction SSOP is used.
4. Before this instruction is used, you need go to ISPSoft -> HWCONFIG -> CPU -> System ->
Redundancy to enable redundancy system.
5. You can only use this instruction in a working redundancy system. That means there should be
a Standby CPU and it should pass the identification check. If there is no other CPU to switch to
or the Standby CPU fails to pass the identification check, this instruction cannot be executed
and an error code will be generated.
Codes Descriptions
Codes Descriptions
0 A successful switchover
1 Failed to switch over; the Standby CPU not passing the identification check
2 Failed to switch over; the Standby CPU does not exist
Example:
When M0 is from OFF to ON and the value in D0 is 0, the system switch from Master CPU to
Standby CPU.