Nortel NT1R20 Description page 171

NT5D33 and NTRB34 Line-side E1 Interface Cards
Note: All idle LEI lines will go off-hook and seize a Digitone Receiver
when the off-hook line processing is invoked on E1 failure. This may
prevent DID trunks from receiving incoming calls until the LEI lines
time-out and release the DTRs.
Daisy-Chaining to MMI
If you plan to install two or more LEIs and to use the MMI, you will want to
daisy-chain your cards together to use one MMI terminal or modem. Make
your selection for this dip switch position based on how many LEIs you are
installing.
MMI Master or Slave
This setting is used only if you are daisy-chaining your cards to the MMI
terminal or modem. It determines whether this card is a master or a slave in
the daisy chain. Select the master setting if there are no LEIs between this
card and the MMI terminal or modem; select the slave setting if there are
other cards in the daisy chain between this card and the MMI.
Tables 35 through 37 show the dip switch settings for Switch #1. Table 38
shows the dip switch settings for Switch #2.
Page 147 of 290
Line cards Description