Module Description; Functional Characteristics - GE 90*-30 PLC Series User Manual

Q

Module Description

Functional Characteristics

Q-2
The Series 90 PLC L W
ON
GE Series 90-30 PLC and an Echelon L
interface with networks that use twisted pair cabling in bus, loop, or free-topology configurations.
The LBIM can support up to 244 network variables (four of which are reserved as configuration
variables) and map these network variables (NVs) into the %I, %Q, %AI, and %AQ PLC memory
references. The Module adheres to the L
interface to the L W
ON ORKS
The LBIM can be located in any rack in any slot (except for the slots in the main rack that are
reserved for the power supply and CPU) in a Series 90-30 PLC. For the most efficient system
operation, the main baseplate is preferred.
The following slots are reserved in the PLC main rack:
Models 331, 340, 341, 351, 352 and later: Slot 0 reserved for power supply
`
Models 311 and 313:
Most parameters are supported to the limits of the L
node. The module supports up to 240 user NVs. The actual maximum number of NVs depends on
the size and type of the NVs, the PLC available memory space (2kbytes each direction), and the
configuration memory budget. The module supports all Standard Network Variable Types
(SNVTs) as listed in the SNVT Master List published by Echelon Corporation as of June 1996.
Each NV must be no more than 31 Bytes in length. NVs can be mapped into PLC memory types
%I, %Q, %AI, or %AQ. NVs mapped to memory types %I or %Q must be of type
SNVT_lev_disc, SNVT_switch, or other bit-represented types.
When an input NV is updated, the data associated with it are copied into the proper PLC input
buffer location. The Store Inputs routine is then called to update the PLC memory during the next
PLC scan. When the API callback notifies the module that an output scan update has arrived, the
data are copied into a holding buffer. This buffer is then scheduled to be checked against the
current value of each NV output. If the data are different, the NV is updated over the L
network if the Min Send Time has expired (only if Min Send Time was configured).
The LBIM has four LED indicators that show the module's operating status. The Service and
Wink functions provided by L
and Indicators").
Series 90™-30 PLC LONWORKS® Bus Interface Module User's Manual – June 1997
Bus Interface Module (LBIM) provides an interface between the
ORKS
W network (Figure Q-1). The LBIM can
ON ORKS
M Layers 1-6 Interoperability Guidelines for the
ON ARK
network.
Slot 0 reserved for power supply (The CPU is built into the
baseplate.)
W are implemented in the LBIM (for details, see "Controls
ON ORKS
Slot 1 reserved for CPU
T protocol and those of the L
ON ALK
W
ON ORKS
W
ON ORKS
GFK-1322A