Transmit/Receive Blocks - Siemens SIMADYN D Manual

3.10.2.3

Transmit/receive blocks

General
information and
connections (I/O)
System- and communication configuring D7-SYS - SIMADYN D
Edition 12.2003
• PRI (transmit priority)
If a transmit request occurs simultaneously, this defines which of the
two communication partners can first transmit. PRI=0 means that the
partner can first transmit; PRI=1 means that the SIMADYN D first
transmits. This data entry must be different for SIMADYN D and the
communications partner.
• BCC (block check character)
This defines whether a block check character is also transferred.
BCC=0 means that no block check character is sent (this corresponds
to procedure 3964, Hamming distance=2); BCC=1 means that a block
check character is sent (corresponds to procedure 3964R, Hamming
distance=4). For SIMADYN D and the coupling partner, this data entry
must be the same.
• LS (transport layer identification)
This defines whether and how the RK512 protocol is to be used.
− LS=0: The RK512 protocol is used, as specified for SIMATIC;
especially for data transfers in the single-word format, the data
words high byte before low byte are transferred ("Big-Endian" or
"Motorola" format).
− LS=1: Protocol RK512 is used, but for single-word format data
transfer, the data words are transferred, low byte before high byte
("Little-Endian" or "Intel" format). For example, this is used for
couplings to COROS.
− LS=2: Protocol RK512 is not used. Data is directly transferred with
the procedure 3964(R).
All transmit- and receive blocks of the process data utility can be used
which have address inputs (AT/AR). To start off with, a unique channel
name must be specified at these connections. This is then followed,
separated by a point (period - separator), by the address data required
for DUST3.
Communications configuring
3-135