Publication 1747-RM001G-EN-P - November 2008
14-4 SLC Passthru Communications
destination equal to 128 plus the processor’s channel 1 network address are
kept and executed by the passthru processor. DF1 Half-duplex Master packets
received with a destination address outside of the valid channel 1 address range
are rebroadcast as slave-to-slave messages. DF1 Radio Modem packets
received with a destination address outside of the valid channel 1 address range
are ignored.
Channel-to-channel passthru is enabled using one of two different status file
bits, depending on whether channel 0 is configured for DH-485 or DF1
protocols. Depending on firmware revision, valid DF1 protocols for passthru
are Full-duplex only or Full-duplex, Half-duplex Master and Radio Modem.
If channel 0 is configured for DH-485, S:34/0 enables and disables
channel-to-channel passthru as follows.
• If S:34/0 is 0 (default setting), channel-to-channel passthru is enabled.
• If S:34/0 is 1, channel-to-channel passthru is disabled.
If channel 0 is configured for DF1, S:34/5 enables and disables
channel-to-channel passthru as follows.
• If S:34/5 is 0 (default setting), channel-to-channel passthru is disabled.
• If S:34/5 is 1, channel-to-channel passthru is enabled.
Additional SLC 5/03 Passthru Status Bits
The SLC 5/03 has two additional status file bits associated with
channel-to-channel passthru. The bits are:
• DF1 Remote/Local Passthru bit (S:34/6).
• Local Passthru Queue Full bit (S:34/7).
The DF1 Remote/Local Passthru bit controls whether DF1 commands
received by channel 0 are passed through to the channel 1 DH-485 network as
remote DH-485 packets (S:34/6=0) or as local DH-485 packets (S:34/6=1).
The DF1 Remote/Local Passthru bit only affects passthru operation when
channel 0 is configured for DF1 and channel-to-channel passthru is enabled
(S:34/5=1)
IMPORTANT
For the SLC 5/05, a valid passthru routing table file
number must also be configured in order to enable
channel-to-channel passthru.