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Rockwell Automation 1794-Lxxxx PhaseManager User Manual

Page 71

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Publication LOGIX-UM001B-EN-P - April 2010

71

Equipment Phase Instructions (PSC, PCMD, POVR, PFL, PCLF, PXRQ, PRNP, PPD, PATT, PDET)

Appendix A

Example:

Relay Ladder

Structured Text

If NOT
Interface_To_Equipment.Equipment_Faults_Cleared
And NOT Fault_Strobe Then

POVR(Shear_One_Phase,Abort,0);
PFL(333);

End_If;

Fault_Strobe := NOT
Interface_To_Equipment.Equipment_Faults_Cleared;

The equipment program watches for the following faults:

• Faulted axis
• Jammed material

If there is a fault, then

Local_Interface.Equipment_Faults_Cleared = 0. This tag is an alias for the
controller-scoped tag Shear_1.

The prestate routine of the equipment phase watches for the equipment program to signal a
fault.

• If Interface_To_Equipment.Equipment_Faults_Cleared = 0 then there is a fault.
• Both Interface_To_Equipment and Local_Interface are aliases for Shear_1, so they have

the same values.

If there is a fault Then

Give the Shear_One_Phase equipment phase the abort command. The POVR instruction
makes sure the command works even if someone has manual control of the equipment
phase through RSLogix 5000 software.

The PFL instruction sets the failure code for Shear_One_Phase = 333.

The Fault_Strobe keeps these actions to a single scan.

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