I have played a bit with the older 6-round electrically-fired smoke dischargers they were considering as a retrofit for the M109 and FASV. The system was a self-contained box at the commander's station and for a turret or hull installation contained 6 dischargers on the left side and another 6 on the right side as well. When fired, they would project from 50m to 100m away from the vehicle (I'd roll [1D6+4] X 10m). I know there are also 8 and 12 round Dischargers as well.
The Controller:
The box had a "Master Arm" switch on the right bottom of the box. This switch put electrical power to the system to prevent an "accidental discharge" of the system.
Next to the Master Arm switch was a Discharger Selector switch with "Left" "Right" and a center setting named "All." This switch selected the left-side discharger (turn to the left), the right-side discharger (turn right), or BOTH dischargers at once when on the center "All" setting.
Over the Master Arm, and Selector switches were SIX Toggle switches numbered 1 thru 6. These would allow the individual firing of each of the 6 dischargers on either one side or both sides based on the setting that the Selector Switch was set to. A SEVENTH Toggle switch was offset slightly to the right of the other 6. This set off ALL of the Dischargers at once.
All of the Toggle switches and the Master arm switch had lift-up protective coverings to prevent accidental firing.
The Munitions:
HC Smoke: The basic munition was HC Smoke. US personnel could see through this thick white smoke with thermal imagers.
Dual Spectrum Smoke: This munition contains an aerosol that blocks IR radiation in addition to HC smoke. Lasers, thermal imagers, and IR sights CANNOT SEE THROUGH THIS SMOKE.
Frag Grenades: These were developed to clear sappers off of tanks but they run into the same trap as "Active Protective Systems," they are very dangerous to friendly troops. They usually deploy from 5m to 30m (1D6 X 5m) from the tank and AIRBURST above it.
Emergency Signal Flares: These come in both visible and IR versions and are just like the signal flares fired from flare guns. These are typically issued to Marine vehicles swimming to shore as a visual signal device in case of emergency.
Illuminating Flares: These are just like ILLUM rounds but 66mm and electrically fired.
Chaff Rounds: These are normally issued to AA guns with radar and are designed to perform just like Chaff from an aircraft. They are used to counter HARM missiles.
The Russian SHORTA system: While the IR Dazzlers on the T90 were too fragile and used too much power to port over to other tanks, the smoke dischargers of the SHORTA system were equipped with an aerosol that would block/absorb laser, IR, and thermal emissions. The aerosol was CLEAR and a tank's day sight could still track and fire at targets. The SHORTA system would, however, block laser-guided munitions and laser rangfinders completely. It was fitted to just about every tank the Soviets built in the '80s.
Matsimus also has a video on a newer type of Discharger shown here...
https://youtu.be/e9RyNdVThjQ