Because RFL™ and Hubbell® have a policy of continuous product improvement, we reserve the right to change designs and specifications without notice.
While the Actel (U12) specifies the port and timeslot of concern, the processor specifies which of the
eight maps is to be used by three address lines (“MAPSEL0” through “MAPSEL2”), completing the
eleven address lines to U11. The three map select lines are controlled by the processor and latched in
U12.
The mapping data read from U11 is contained in “MD1” through “MD8”. This data is directly used as
lookup address (port and timeslot as described in section 3.1.2.3.1) information for the payload data
memory (U10). As with the receive data, one m
ore address line is added to access the signaling data.
The transmit payload and signaling data are sent out of the “R” side of U10 and into U12 for parallel-
to-serial conversion and transmission.
The transmit payload data is sent to the framer via the “TSER” signal, the signaling data is “TSIG”.
U12 also generates the transmit clock “TCLK” and sync “TSYNC” signals for the framers.
3.1.2.4 DACS MODULE HOT-STANDBY MODE
The hot-standby mode is a special configuration that may be used between two M-DACS nodes. Ports
1 and 2 of one M-DACS are connected to ports 1 and 2 of the M-DACS at the other location.
In hot-standby, the transmit of port 1 and 2 is always receiving data from the receive of port 5. Port 5
transmits the data received from either port 1 or 2. The port being used to receive the remote data will
only be swapped if a problem is detected with the presently active port.
This minimizes the number of switches by not specifying either port 1 or 2 as “primary”, and thus not
reverting back to it when the channel is cleared. Additionally, by always transmitting on both output
ports, the inactive port is always primed with live data, thus minimizing any switching disturbance.
The functions of ports 1, 2, and 5 are pre-defined when in hot-standby mode. A second hot-standby
function is provided on ports 3, 4, and 6. This second hot-standby function is fully independent of the
first.
M-DACS-T1 RFL Electronics Inc.
October 25, 2004 3-9 (973) 334-3100
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