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How does the M580 or Quantum Ethernet RemoteIO Drop Custom RPI work?


The M580 or Quantum Ethernet RemoteIO Drop Custom RPI feature is also dependent upon the configuration of the MAST task. (Below information is extracted from the Quantum EIO Remote I/O Modules Installation and Configuration Guide page 73-74). Below is a FTP link to the manual.

CRA->CRP RPI Inputs: The RPI is the input refresh rate at which the adapter module sends inputs to the 140 CRP 312 00 module or the M580 CPU. The RPI is set in the subscribe field for the adapter on the remote I/O drop.
1.  periodic mode: default value = 1/2 MAST period
2.  cyclic mode: default value = 1/4 MAST watchdog timeout period
3.  valid values: 2...1500 (ms)

CRP->CRA RPI Outputs: Outputs are passed from the 140 CRP 312 00 module or the M580 CPU to the adapter. Set the output refresh rate with the Application Trigger value (CRP->CRA RPI) at the end of the CPU MAST task:

1. periodic mode: default value = 1.1 * MAST period. The value output is sent at the end  of the actual MAST period.
2. cyclic mode: default value = 1/4 * watchdog timeout period. The value output is sent at the end of the actual MAST period.

NOTE: The default value for the watchdog timer is 250 ms. If the MAST task does not finish within the watchdog period, the process times out. If the watchdog is greater than 4 times the MAST period, the drops could switch to fallback while the CPU is running. For example, MAST period = 20 ms, logic execution = 90 ms, watchdog time = 100 ms. You cannot edit this value. All outputs are published synchronously or at the execution of the MAST task:

1. synchronously: immediately at the end of the MAST task
2. execution of IU_ERIO: You can only generate outputs when you use the IU_ERIO function block (see page 101). (See the note below.)

NOTE:
1. When the Periodic mode is selected for the MAST task, the Period value allows the complete execution of the logic. (The MAST can overrun when its execution time exceeds this value.) Valid values: 1...255 ms (increment: 1 ms).

2. When Cyclic mode is selected for the MAST task, the outputs are sent upon the completion of the task. The Watch Dog value (10 ... 1500 ms, default = 250) should be greater than the execution time. Valid values: 10...1500 ms (increment: 10 ms, default = 250 ms).


Attached is the Quantum Ethernet RIO Manuals.
 
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