Rockwell Automation PLC-5 Fieldbus Solutions for Integrated Architecture User Manual - Manual (Page 66)

Publication 1757-UM006A-EN-P - May 2002
2-22 Integrating Fieldbus into Rockwell Automation Logix System
ProcessLogix also ignores the following illegal mode combinations as
defined by the Fieldbus Foundation.
• If ROut is set, RCas may not be set. If it is set, it will be ignored.
• The Auto and Man bits must always be of opposite states. If
neither Auto nor Man or both are set, and the ROut, RCas, or Cas
mode is set, Auto mode will be assumed with Man cleared.
Likewise, If neither Auto nor Man or both are set, and neither
ROut, RCas, nor Cas mode is set, Man mode will be assumed
with Auto cleared. For the OOS mode, the Man bit should be set
unless it is not permitted. If Man is not permitted, the Auto bit
should be set unless it is not permitted. If neither Auto nor Man
is permitted, the OOS bit should be set.
ProcessLogix adheres to the following additional rules for setting
fieldbus target mode bits in Table 2.G for its MODE supported subset
of combinations.
IMPORTANT
An operator needs an access level of ENGR or higher
to invoke the OOS mode or to return a block to an
in-service mode.
Table 2.G Additional rules for setting fieldbus target mode bits
Fieldbus Mode Rule
OOS When setting as the target mode, obtain the target mode, preserve the Auto and Man bits, set
the OOS bit, and optionally reset all the other bits. Reject the request, if the access level is not
ENGR or higher.
IMan This is a Read Only parameter and can not be set as the target mode. Never set the IMan as the
target mode.
LO This is a Read Only parameter and can not be set as the target mode. Never set the LO as the
target mode.
Man When setting as the target mode, set the Man bit and reset all the other bits. Reject the
request, if the current mode is OOS and the access level is not ENGR or higher.
Auto When setting as the target mode, set the Auto bit and reset all the other bits. Reject the
request, if the current mode is OOS and the access level is not ENGR or higher.
Cas When setting as the target mode, set both Cas and Auto bits and reset all the other bits. Reject
the request, if the current target mode is OOS and the access level is not ENGR or higher.
RCas When setting as the target mode, set both RCas and Auto bits and reset all the other bits.
Reject the request, if the current target mode is OOS and the access level is not ENGR or higher.
ROut When setting as the target mode, set both ROut and Auto bits and reset all the other bits.
Reject the request, if the current target mode is OOS and the access level is not ENGR or higher.
Normal When setting as the target mode, read the MODE.NORMAL value and write to the
MODE.TARGET. Reject the request, if the current target mode is OOS and the access level is not
ENGR or higher.