Emerson manual Capabilities, RESOURCE BLOCK FEATURES and FEATURES SEL, Rosemount 848L

Rosemount 848L

Reference Manual

00809-0100-4696, Rev AA September 2004

Capabilities

Virtual Communication Relationship (VCRs)

There are a total of 20 VCRs. Two are permanent and 18 are fully configurable by the host system. 25 link objects are available.

Network Parameter	Value
Slot Time	8
Maximum Response Delay	4
Maximum Inactivity to Claim LAS Delay	60
Minimum Inter DLPDU Delay	7
Time Sync class	4 (1ms)
Maximum Scheduling Overhead	21
Per DLPDU PhL Overhead	4
Maximum Inter-channel Signal Skew	0
Required Number of Post-transmission-gap-ext Units	0
Required Number of Preamble-extension Units	1

Host timer recommendations

T1 = 96000

T2 = 1920000

T3 = 480000

Block Execution times

Discrete Input = 40 ms Discrete Output = 40 ms Multiple Discrete Input = 40 ms Multiple Discrete Output = 40 ms

RESOURCE BLOCK

FEATURES and

FEATURES_SEL

The parameters FEATURES and FEATURE_SEL determine optional behavior of the Rosemount 848L.

FEATURES

The FEATURES parameter is read only and defines which features are supported by the Rosemount 848L. Below is a list of the FEATURES the Rosemount 848L supports.

UNICODE

All configurable string variables in the Rosemount 848L, except tag names, are octet strings. Either ASCII or Unicode may be used. If the configuration device is generating Unicode octet strings, you must set the Unicode option bit.

REPORTS

The Rosemount 848L supports alert reports. The Reports option bit must be set in the features bit string to use this feature. If it is not set, the host must poll for alerts.

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