MC2000 and MC2500 deskset question

[911-EMT]

Hi I am working on a mc2000 and a mc2500 deskset in “advanced single channel” mode setup for “tone” keying with “stat alert” in “parallel status” with a “4 wire interface” to access different towers using a “simplex base stations” in different areas trout the city with heavy voice traffic over the frequency but the problem I have is that the mc2000 and mc2500 dos not transmit when their is traffic on the frequency so the dispatcher can not put out a job if two crews are communicating or their is a open carrier not like the old c200 consol that could key up the tower when the dispatcher pressed ptt regardless if their is traffic or not on the frequency, so my question now is this consol not made for what I am using it or I just missed something in the rss like a buzz lockout option.