Installation manual

Publication 1747-RM001G-EN-P - November 2008
SLC Communication Channels 13-19
This word is located in memory at S:99. If, S:34/3 is set, data in this
memory location is transmitted every time the processor passes the
DH+ token. Note that all other DH+ nodes see this data.
• Global Status File.
This file is located in memory at S:100 to S:163, representing one
memory location for each of the 64 possible nodes on the DH+
network. As other nodes transmit Global Status information with their
token passes, the SLC 5/04 processor collects this information and
stores it in the Global Status File. Memory location S:100 corresponds
to node #0 (octal), S:101 corresponds to node #1 (octal), and S:163
corresponds to node #77 (octal).
One word of every node’s Global Status File is updated each token pass. This
can function as a high-speed broadcast message, useful for status passing and
synchronization of processors.
If the Global Status Word Transmit Enable bit (S:34/3) and Global Status
Word Receive bit (S:34/4) are never set, you can use the Global Status File
(S:100 to S:163) for other storage uses. If these bits are reset, this area in the
System Status File is never altered by the SLC 5/04 processor, even after a
power cycle to the processor.
S:34/3 Global Status Word Transmit Enable Bit
Transmission of the Global Status Word is enabled by setting bit S:34/3 in the
status file. If this bit is set (1), the processor transmits the data in S:99 with
every DH+ token pass. If this bit is not set (0), the processor passes the token
and does not attach the Global Status Word. This bit is dynamically
configurable and the default setting is zero. Keep the following guidelines in
mind when using the Global Status Word Transmit Enable bit.
• If this bit is not set, the DH+ Token Pass transmitted out Channel 1 will
contain no Global Status Word bytes
• If this bit is set, but the SLC 5/04 is not in RUN mode, REMote Run, or
one of the three test modes, the DH+ Token Pass transmission will
contain a 2-byte Global Status Word of 0x0000.
• If this bit is set and the SLC 5/04 is in RUN mode, REMote Run, or one
of the three tests modes the DH+ Token Pass transmission will contain
a 2-byte GSW equal to the value in S:99 (Global Status Word). The
word is also placed in the 64-word Global Status File (S:100 to S:163) in
the location corresponding to the DH+ node address associated with
the SLC 5/04 processor.
For example, if the SLC 5/04 processor is operating at octal address 22
(18 decimal), the transmitted GSW is written to word S:118.