Sm_support bits, Sm agent objects, System application clock time synchronization – Flowserve 400MD Logix User Manual
Page 67: Sync and scheduling objects

8
Identify (manager)
no
9
Locating function blocks (manager)
no
10
FMS server role
yes
11
Application clock synch (timeslave)
yes
12
Scheduling function block
yes
13
Application clock synch (time publisher)
no
14
to31Reservedforfutureuse.
no
SM_SUPPORT Bits
Any bit (of the object SM_SUPPORT) will be set that corresponds to a supported feature listed in Table 8.23. The resulting value in the object SM_SUP-
PORT is 1C1F (hex).
SM Agent Objects
Four SM agent objects are contained in the SMIB object dictionary. One object, SM_SUPPORT, was described previously. The three other objects are timers
associated with SM operations. Table 8.22 identifies the SM Agent objects with their object directory index and default values.
Table 8.22 SM Agent Objects
Object
Description
OD
Index Default Value
SM_SUPPORT Variable that indicates the features supported by SM
in this device. See Table 8.22, Logix 3400MD Digital
Positioner SMIB Object Dictionary
258
0x1C1F
T1
Value of the SMstep timer in 1/32 of a millisecond
ticks.
259
96,000* (3 seconds)
T2
Value of the SM set address sequence timer in 1/32 of
a millisecond ticks.
260
1,920,000* (60 sec-
onds)
T3
Value of the SM set address wait timer in 1/32 of a
millisecond ticks.
261
480,000 * (15 seconds)
* The default value is specified by the communications profile for the application area
System Application Clock Time Synchronization
Each link in a fieldbus network contains an application clock time publisher responsible for distrib uting application time on the link.
A clock synchronization message is periodically sent by the time publisher to all fieldus devices. The application clock time is independently maintained in
each device based on its own internal crystal clock.
Clock synchronization provides the capability for devices to time stamp data (events and alarms when they occur).
Sync and Scheduling Objects
These objects are used by system management to provide application clock synchronization and macro cycle scheduling for the device. Table
8.23 identifies the sync and scheduling objects with their object directory index and default values.
Table 8.23 SM Sync and Scheduling Objects
Object
Description
OD
index
DefaultValue
CURRENT_TIME
The current application clock time.
262
Dynamic
LOCAL_TIME_DIFF
Used to calculate local time from CURRENT_TIME.
263
0
AP_CLOCK_SYNC_INTERVAL
The interval in seconds between time messages on the link (bus).
264
Set by SM (mgr.) during address assignment
Logix 3400MD Digital Positioner LGENIM3405-02 11/13
67