I am currently using MX-3000 with MRF-350 base station for my family room, Mx-850 with MRF-350 for my master bedroom and MX-850 with MRF-350 for my dining.

Since i am using the same model of TVs at all locations, so i have set all the MRF-350s with different IDs and I even assigned the IR port with only RF signal sending out.

However, whenever someone in Dining Room/master bedroom controlling the TV and at the same time, i control the TV at family room, the signal from Dining Room/master bedroom would interference my control at family, i.e. the TV at family will respond to the signal from Dining Room/master bedroom... It reli annoys me so much.

All the MRF-350s have its own ID with the IR emitter port assigned, with IR blaster "off".. anyone has any ideas why this happen? All the MRF-350s are put together in the same location, next to each other.. does it matter?

The MRF-350 will receive all commands sent by any MX-3000 in your house.

Only the right commands containing the right ID will be let through.

If 2 person's presses a command at the same time can cause problems, only 1 at the time can be read.

Maybe the command from the person in your dinning room will be received and read, your might have been let aside.

I had this problem before and this is how I understood it.

Correct me if i'm wrong.

Before going further (it's not 100% clear in your post)...you have set the ID on the bottom of each base station AND in the respective programming to match something other than 0 (zero) on all three AND all three are different IDs, correct?

Like tweeterguy stated if you are running 3 MRF-350 units with 3 seperate remotes for 3 seperate zones then you must set each MRF unit to a differen ID then set each remote to its appropriate ID as well,,, example

Master Bedroom
MRF set to ID 1
Local URC remote set to ID 1 via RF control options in the editor

Guest Bedroom
MRF set to ID 3
Local URC remote set to ID 3 via RF control options in the editor

Theater Room
MRF set to ID 5
Local URC remote set to ID 5 via RF control options in the editor

make sure to disable the front IR blaster in the RF options as well for ALL units

Can you even use an MX850 with the new MRF350? The MX850 is a broad band transmitter, and the MRF350 is a narrow band receiver.

The newer MX-850's have the narrowband transmitter.

check out the sticky at the top of this forum regarding narrow band compatible remotes and build dates.

I have this same problem with my neighbor. We both have the same cable box, and normally, there is no interference, except for when we both try and do something to the cable boxes at the same time. I'll be pressing channel up, and then all of a sudden, I'll see a 2 pop up on my screen or something like that. Seems to be that if an MRF is receiving two commands for a similar device at the same time from two different remote IDs, the remote ID gets "lost" sometimes, and will the MRF will output any command it receives. URC needs to make their basestation ID system a bit mroe "bulletproof".

You need to use the (i) series product. it is on a different megahertz. this will solve your problem on the 2 most used rooms...

To make myself a little bit clear...
i have set different ID to different base station and set the corresponing ID to the remote control as well.
i.e. Family Room: MRF350 ID: F
MX3000 ID: F with only RF signal and front IR blaster off
Master Bedroom: MRF350 ID: 1
MX850 ID: 1 with only RF signal and front IR blaster off
Dining Room: MRF350 ID: 7
MX850 ID: 7 with only RF signal and front IR blaster off

I tried to set the ID apart from each other... but seems it doesn't help much.

Re: 8ate8
ur situation is exactly what i experienced in my house... While i was switching my family TV to watch cable TV and someone in dining room switching TV channels at the same time, some signal came into my family tv and finally tv switched to a wrong channel. it seems mx3000 is lost in the signal flood....

How can this situation be improved???

You may have IR bleeding through the coax lines....seen that a couple times. Solution would be to make sure all coax connections are tight and with sealed compression fittings and/or a DC blocker.

You may also have IR bleeding out of the emitters from one cable box to another. Solution is to mask them with non-opaque material (i.e. an ir shield) or place the emitters inside the cable boxes.

You could have defective equipment.

If I recall when 2 remotes issue RF commands at the same time there is a brief moment when the 'gate' is open to receive anything.

The rfx-250 antennas should be located in each corresponding room (that's what they're designed for). If not try relocating them and see what happens and maybe try removing the antenna whip also.