Reference MVI46-N2
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SLC Platform
Johnson Controls N2 Communication Module
ProSoft Technology, Inc.
Page 49 of 68
October 27, 2008
5.2.2 Data Flow Between the MVI46-N2 Module and the SLC
Processor
The following section describes the flow of data between the two pieces of
hardware (SLC processor and MVI46-N2 module). Each port on the module is
configured to emulate a Johnson Controls N2 slave device. The operation of
each port is dependent on this configuration.
Slave Driver
The Slave Driver Mode allows the MVI46-N2 module to respond to data read and
write commands issued by a master on the Johnson Controls N2 network. The
following flowchart describes the flow of data into and out of the module. The
Module Setup section provides a list of the parameters that must be defined for a
slave port.
All write requests will be passed directly to the processor. The following
illustration shows the data flow for a slave port.
5.3 Cable
Connections
The application ports on the MVI46-N2 module support RS-232, RS-422, and
RS-485 interfaces. Please inspect the module to ensure that the jumpers are set
correctly to correspond with the type of interface you are using.
Note:
When using RS-232 with radio modem applications, some radios or modems require
hardware handshaking (control and monitoring of modem signal lines). Enable this in the
configuration of the module by setting the UseCTS parameter to 1.
