Micromod Micro-DCI: 53MC5000 MicroLink - Manual (Page 6)

2.0 MICROLINK OVERVIEW
MicroLink is a low-cost, high performance interfacing network for 53MC5000 Process Control Sta-
tions (PCS), 53SU5000 SUPERVISOR-PC units, and PC units with the 53WS5000 product pack-
age installed. A Single MicroLink network supports 32 nodes of which four can be assigned to
53SU5000 SUPERVISOR-PC units.
Each 53SU5000 SUPERVISOR-PC unit must have a MicroLink SUPERVISOR board and software
installed to function on the network. The SUPERVISOR-PC unit provides Engineering Mode and
Operator functions for the network system. Engineering Mode functions are used for system initiali-
zation, to create animated displays, and to build the underlying process control programs. Opera-
tor functions allow an operator (if required) to view the animated displays that reflect the status of
the process(es) monitored by the network and to intervene, if necessary, by the SUPERVISOR-PC
unit operator’s keyboard.
Each 53WS5000 product package must include the MicroLink SUPERVISOR board and software in-
stalled in a PC unit to function on the network. The software in the 53WS5000 product package
provides the tools to configure online instruments or offline databases that can be downloaded to
instruments. It provides a graphic configuration module that is used to symbolically design control
strategies for the 53MC5000 PCS. Each graphic control strategy can be compiled into code for
downloading to a PCS. The software also provides an F-TRAN compiler; SUPERVISOR utilities to
create files for later transport to SUPERVISOR-PC units; a Documenter for hardcopy output (the
Documenter has an optional feature to capture a PCS display for storage and printing); the ability
to menu select other user applications; and a displayable Instruction Bulletin used for referencing.
A PC unit with the appropriate 53WS5000 hardware and software options installed can function as
a host to SUPERVISOR-PC units via a DECnet interface. As a host to the SUPERVISOR-PC
units, the PC unit executing the software can perform file management functions to put, get, delete,
or archive files.
A 53MC5000 Process Control Station in the MicroLink network is a multi-configurational device ca-
pable of being set up to perform a wide range of process application control strategies. To function
on the network, a PCS must have Expansion Ready capabilities and a minimum communications
option that is a Single High Speed Communications Board (e.g., model number
53MC5000
◆◆◆ B ◆◆◆◆◆ D ◆ where B = Expansion Ready, D = Single High Speed Communica-
tions Board Only, and ◆ = other options).
MicroLink network communication is peer-to-peer. Any node (53MC5000 PCS, 53SU5000 SUPER-
VISOR-PC unit or PC unit with the 53WS5000 product package installed) requiring access, moni-
tors the network for activity. If the network is clear, it sends a command packet (COMMAND)
containing a destination identifier and data. Although the command packet appears on the entire
network, only the node having the correct identifier can capture the incoming data. To indicate a
successful data transfer, a response message (RESPONSE) is put onto the network by the receiv-
ing node. In the event two or more nodes detect network inactivity and attempt to send command
packets, a data collision occurs preventing the messages from being sent. Each sending node de-
termines the collision occurred when a response is not received within a preset time. When the
node detects the collision, it attempts a retry.
Section 2. MicroLink Overview
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