MD side: connect the tie lines to TLU80 board, you should have the ground wire work properly in order to get this work OK.
route parameters:
ROCAI:ROU=1,SEL=011000000000001,TRM=5,SERV=2110000000,TRAF=03151515,SIG=111000000000;
RODAI:ROU=1,TYPE=TL22,VARC=032F0032,VARI=00012240,VARO=43011100;
ROEQI:ROU=1,TRU=1-1&&1-4,EQU=1-0-30-0; /* for lines to equipment */
RODDI

EST=4,SRT=1,ROU=2;
change the nessacry
BP side: in trunk parameters activite the command by the parameter:
command 5401 create a route
command 1201 choose one of the following
08 = Sweden, E&M signaling *)
09 = Continuous E&M signaling, A-format *)
10 = Continuous E&M signaling, D-format *)
11 = Discontinuous E&M signaling *)
command 1302 ---> 0 = Decadic impulsing
command 1023 ---> 2 = Trunk to a private exchange, tie line (TIE LINE)
in route paramters predigits should be the first digit of the MD number plane.
that's it and it should work ok