ProSoft Technology MVI56-S3964R - Manual (Page 54)

MVI56-S3964RT ♦ TControlLogix PlatformT Reference
TSiemens 3964R ProtocolT
Page 54 of 78 ProSoft Technology, Inc.
If both partners want to send a job (3964R with RK512) or data (3964R without
RK512) at the same time, the resulting initialization conflict will be solved through
the high/low priority setup. In such a case one partner will be allocated high
priority and the other one low priority. Thus, in case of an initialization conflict the
device with low priority will defer its job whereas the device with the high priority
will be able to send a job.
The safety of data transmission on the line is guaranteed by a BCC checksum.
You should have sufficient knowledge about the 3964R protocol in order to
understand the operation of the driver for the MVI56-S3964R and to make
efficient use of the example programs.
MVI56-S3964R Operation
The protocol realized on the MVI56-S3964R has the following special features:
ƒ
Immediately after power-up and completion of the internal/external
initialization procedures the MVI56-S3964R with installed 3964R protocol is
ready to serve as an interface between a ControlLogix processor and one or
two communication partners using 3964R protocol. The parameterization of
the module is realized through a configuration file. This is where a
differentiation between the communication modes 3964R with RK512 and
3964R without RK512 takes place.
ƒ The communication mode 3964R without RK512 supports processing of up to
512 bytes.
ƒ The serial transmission parameters are optional and can be allocated
independently to each interface. Possible baud rates are 300 to 115200. The
following parity setups are possible: Even, Odd and None.
5.2.3 General Concepts
Module Power Up
On power up the module begins performing the following logical functions:
ƒ
Initialize hardware components
o
Initialize ControlLogix backplane driver
o
Test and Clear all RAM
o
Initialize the serial communication ports
ƒ Read module configuration from the Compact Flash
ƒ Initialize Module Register space
ƒ Set up the communication interface for the debug/configuration port
When this initialization procedure is complete, the module will begin
communicating with other nodes on the network, depending on the configuration.
April 17, 2008