TC3x Multiplexer User's Guide
TC3x_UG_01_V03.10 -
Released
Page 38/50
10.01.2002
8.3.2 DLC Establishment
The multiplexer control channel must be set up as the first channel followed by all other DLCIs. To do
so, a SABM frame (see Section 8.2.3) must be sent to the TC3x. The TC3x responds with either a UA
frame – i.e., the DLCI was set up, or with a DM frame if the DLCI was not set up.
No provision is made for repeating the request if a response is not received.
The state machine requesting the multiplexer control channel DLCI = 0 is the "initiating station", while
the other is called the "responding station".
Customer
µC
TC3x
SABM: P = 1
Address Field = DLCI of channel to be established
UA: F = 1, DLCI is being established
DM: F = 1, not ready, DLCI is not established
Address Field = DLCI of requested channel
8.3.3 Information transfer
A response is not essential for every command – for example, unsolicited code does not require a
response.
Customer
µC
(Initiator)
MC35
(Responder)
UIH:
P = 0, C/R = 1
UIH:
P = 0, C/R = 0
8.3.4 DLC release
Customer
µC
TC3x
DISC: P = 1
UA: F = 1
DM: F = 1
responding station is
already disconnected
No provision is made to repeat the request if no response is received.
Figure 19: DLC Establishment
Figure 20: Information transfer
Figure 21: DLC release
