A follow-up question was asked over at Mordel's that was answered in the errata, but it generated an additional question that does not seem to be addressed here officially, so I am officially asking for an answer.
According to Void-Signature Systems rules, a Mech "with this system may not mount a Chameleon Light Polarization Shield, Null Signature System, or Stealth Armor. Any Satellite Uplink systems, Targeting Computers or C3 equipment cannot be mounted either" (TacOps, pg. 349).
And TacOps errata added "When the Void-Signature System is engaged, any ECM on the unit has no effect, other than to make the
Void-Signature System functional" (TacOps Errata 3.03, pg. 70). Before the errata, the unit was considered to have been under the effect of its own ECM.
The question that was generated is: can a unit with a Void Signature System equip an Active Probe (or similar) system (other than NOVA CEWS)?
Conditional follow up: If yes, does the Active Probe system generate an effect while Null Signature is engaged?
My reading of the rules and previous mechanics is 'yes' they can mount these systems, but the systems generate no effects while Null Signature is engaged.
Suggested errata: "When the Void-Signature System is engaged, any ECM and Active Probe systems on the unit have no effect, other than the ECM serving to make the
Void-Signature System functional."
