Reference MVI46-S3964R
♦
SLC Platform
Siemens 3964R Protocol
ProSoft Technology, Inc.
Page 47 of 74
5.2 Functional
Overview
5.2.1 Products in the Environment
The 3964R protocol can be installed in all local SLC chassis with at least one
controller.
You can obtain more information about SLC and the SLC environment through
your Rockwell Automation branch office.
Product Compatibility
The communication between the MVI46 and the SLC processor is realized
through M0/M1 data transfer.
5.2.2 3964R Protocol Overview
The 3964R Protocol in General
The 3964R protocol defined by Siemens is used for bi-directional data exchange
between two peers through a bit-serial point-to-point connection. This protocol
may be additionally embedded in the RK512 telegram level. If 3964R is used with
RK512, each participant can send jobs to its partner and has read
(DB-FETCH)
and write access
(DB-SEND)
to the partner's data. The data exchange is realized
in the form of messages and response messages. The maximum user data
volume is 512 byte per job and 128 byte per message.
3964R without RK512 allows only block wise sending and receiving of data. The
detailed handshake procedure through messages and response messages is not
applicable in this case.
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 MVI46-S3964R and to make
efficient use of the example programs.
MVI46-S3964R Operation
The protocol realized on the MVI46-S3964R has the following special features:
April 17, 2008
