Digital Output from 888/16 isn't compatible with Digital Input of TC M2000 & PCM 80

[beerbr]

Now I'm using 888/16 with Protools and I'm using with external effects... TC M2000, Lexicon PCM 80 & 90. Now I've problem that I can't connect Digial link between my 888 and Effects. My M2000 and PCM 80 (PCM 90 has no problem) can't lock the incoming digital signal that send from my 888. I've checked that all 888 digital out is working (sending signal to PCM 90 or Apogee PSX-100 or O2R has no problem). And also I've checked that the digital input of my TC M2000 and PCM 80 are working too (The digital out from my PSX-100 or O2R has no problem). Please help me!! Is there anything I can config to use the Digital link??

Thank you very much..
T.Paul