S84 - Adjustable Start Up (ASU) Negotiation

Description
S84 selects the type of start up used by the modem during Express 96 operation. This feature uses an adaptive start up time (as opposed to a fixed start up time) in the re-synchronizing algorithm for Express 96 (9600 bits/s HDX) operation, which improves the turn around time in most synchronous applications. The re-synchronization time is controlled by the length of time since the last transmission, varying from 80 ms to 3030 ms. ASU is not as efficient as ping-pong, but it can lead to throughput improvements in many environments. This S register allows the user to enable and disable ASU negotiation in addition to selecting the mode of operation. Invalid value write attempts returns the ERROR result code and does not change the register value.

Type
Value

Value range
0-4, 128-132; Factory default - 129

Stored by &Wn
yes

Displayed by &V
no

Bit Map

Bit          Description                            



0, 1, 2      0 - fixed start up                     


             1 - both sides fast ASU                


             2 - both sides smooth ASU              


             3 - local fast, remote smooth          


             4 - local smooth, remote fast          



3, 4, 5, 6   reserved (set to zero)                 



7            1 - ASU negotiated                     


             0 - ASU not negotiated

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