Control mode interaction, Fieldbus block modes versus processlogix modes, Control mode interaction -19 – Rockwell Automation PLC-5 Fieldbus Solutions for Integrated Architecture User Manual User Manual

Page 63: Fieldbus block modes versus processlogix modes -19

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Publication 1757-UM006A-EN-P - May 2002

Integrating Fieldbus into Rockwell Automation Logix System 2-19

Control Mode Interaction

Fieldbus Block Modes Versus Processlogix Modes

Every fieldbus function block including Resource and Transducer
blocks contain the MODE_BLK parameter. This structured parameter
consists of the Actual, Target, Permitted, and Normal modes. Refer
to About Modes of Operation on page 1-8
for descriptions of the eight
modes.

For use within ProcessLogix, the structure of the MODE_BLK
parameter is expanded to add MODE to the existing Actual, Target,
Permitted, and Normal modes as outlined in Table 2.C.

Table 2.D shows how ProcessLogix modes are mapped to fieldbus
ones.

Table 2.C Mode Descriptions

ProcessLogix Mode
Structure

Data Type

Description

FIM Action

MODE

Enumeration

Write Only
ProcessLogix style mode enumeration
MAN, AUTO, CAS, NORMAL, BCAS, NONE

The FIM captures all writes to
MODE and maps valid changes to
MODE.TARGET.

MODE.TARGET

Enumeration

Read/Write
Target mode
OOS, MAN, AUTO, CAS, RCAS, ROUT

If the value NORMAL is written to
the MODE.TARGET, the FIM
replaces it with the value from
MODE.NORMAL.

MODE.ACTUAL

Enumeration

Read Only
Actual Mode
OOS, IMAN, LO, MAN, AUTO, CAS, RCAS, ROUT

MODE.PERMITTED

Bitstring

Read/Write
Permitted mode
MAN, AUTO, CAS, RCAS, ROUT
OOS is always permitted

If a new MODE.NORMAL value is
entered, it is validated against
the MODE.PERMITTED values.

MODE.NORMAL

Enumeration

Read/Write
Normal mode
MAN, AUTO, CAS, RCAS, ROUT
OOS is not Normal

If a new MODE.NORMAL value is
entered, it is validated against
the MODE.PERMITTED values.

Table 2.D Mapping ProcessLogix Modes to Fieldbus

ProcessLogix Mode

Fieldbus Mode

Comment

MAN

Man

AUTO

Auto

CAS

Cas

NORMAL

Normal

When setting as target mode, read MODE.NORMAL value and write to MODE.TARGET.

BCAS

Error

Not used in fieldbus blocks. Attempt to set to target is illegal.

NONE

Error

Not used in fieldbus blocks. Attempt to set to target is illegal.

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