If Group Serv D3=1 then MOW is provided by TMU input 1 (MOH1) or input 2 (MOH2). Which input (1 or 2) depends on AS parameter 139. This is a system wide parameter which does a number of things that can be chosen by accumulating a number of values. If value 32 is chosen then "Music on Hold special Message shall be provided". This means that MOH2 (input number 2)is used for MOW for ACD/Hunt groups. This way it is possible -for example- to use MOH1 for "normal" music on hold (for parking by normal extensions always MOH1 and never MOH2 is used) and MOH2 for ACD/Hunt groups.
If group Serv D3=2 then MOH is only provided after RVA message. This means that -for example- if a group has only repeat queue message programmed the MOH/MOW is played after the repeat queue message. The input (MOH1 or MOH2) is again dependent on AS 139.
Then BC11 came with continuous announcement... The cont. ann. can have values 0-254 (BC12) Cont. ann. is played -in a fully "RVA-equiped group"- after the group queue announcement and only interrupted by the repeat queue announcement. Cont. ann. can be used as a normal announcement (values 1-250) but the cont. ann. values 251-254 are special kind of "announcements". If cont. ann. 251 is chosen then MOH1 (on TMU) is used. If cont. ann. 252 is chosen then MOH2 (on TMU) is used. If cont. ann. 253 is chosen then MOH3 (on TMU) is used. If cont. ann. 254 is chosen then silence is used.
Question: Now what happens if group Serv D3=0 and in command RAGAI for example Cont=251 is used? Answer: MOH/MOW is played from input nr. 1 on TMU.
Question: Now what happens if group Serv D3=0 and in command RAGAI for example Cont=252 is used? Answer: MOH/MOW is played from input nr. 1 on TMU.
Question: Now what happens if group Serv D3=2 and in comand RAGAI for example Cont=251 is used? Answer: MOH/MOW is played from input nr. 1 on TMU after RVA message. If no rva is programmed for group then no MOW is played.
So the continuous announcement (CONT in RAGAI/RAGAC) programming overrides (for a great deal) the group (SERV) parameter.
Then finally: Another two system parameters (154 and 177)state the way the TMU('s) are used.
AS 154, possible values 0 , 1 or 2. Parval=0 no moh input used. Parval=1 1 moh input used, meaning MOH1 (the bottom input on the board) Parval=2 moh1 and moh2 used (the bottom 2 inputs). I think default value for this parameter is 2. Leave it that way. It is not possible to increase the PARVAL value of AS 154 after it has been changed to a lower value, unless the TMU board is removed and re-inserted.
AS parameter 177: Selection of tone instead of music. parval=0 input 1-3 are used for music parval=1 channel 1 (MOH1) tone instead of music parval=2 channel 2 (MOH2) tone instead of music parval=3 channel 3 (MOH3) tone instead of music parval=7 all channels (MOH1&&MOH3) tone instead of music
Remark: MOH3 is only available if more then 1 TMU in a Lim. MOH3 is placed on second TMU if parnum 154=2. MOH3 is placed on third TMU if parnum 154=1.
Total picture in this table:
Parnum 154=0 Parnum 154=1 Parnum 154=2 1 TMU tone Moh1 on TMU 1. Moh1 and 2 on TMU1 2 TMUÆs tone Moh 2 on TMU 2 Moh3 on TMU2 3 TMUÆs tone Moh 3 on TMU 3 No Moh on TMU3
MOH1 is on 4A26 & 4A28 on the board (tmu 1). MOH2 is on 4A18 & 4A20 on the board (tmu 1) if parnum 154=2. MOH2 is on 4A26 & 4A28 on the board (tmu 2) if parnum 154=1. MOH3 is on 4A26 & 4A28 on 3rd board (tmu 2) if parnum 154=1. MOH3 is on 4A26 & 4A28 on 2nd board (tmu 3) if parnum 154=2.