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- Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU
- Path: sparky!uunet!usc!sdd.hp.com!zaphod.mps.ohio-state.edu!uwm.edu!psuvax1!psuvm!auvm!MONTCOLA.BITNET!MARK
- Message-ID: <IBM-MAIN%92121512464474@RICEVM1.RICE.EDU>
- Newsgroups: bit.listserv.ibm-main
- Date: Tue, 15 Dec 1992 13:17:04 EST
- Sender: IBM Mainframe Discussion list <IBM-MAIN@RICEVM1.BITNET>
- From: Mark Bandak <MARK@MONTCOLA.BITNET>
- Subject: Help with NRZ vs NRZI on SYS/36 ...
- Lines: 36
-
- Folks:
-
- Sorry if this is not the 'exact' correct forum; but I need help from
- someone with a 'good' SDLC background. (excuse x-posts)
-
- Scenario: just converted (outside our dept.) a SYS/36 with a 5294
- remote controller from modem to T1 (9.6K). From a variety of manuals
- the only way we could get the 5294 to work was to change the SDLC
- parms from NRZI to NRZ. In GA21-9369-2 it is stated (elsewhere as well)
- 'The initial setting of this bit is recommended to be NRZI (0,off) for
- EIA interface with analog modems/DCEs and NRZ (1,on) for DDSA, XLCA,
- and EIA interfaces, when EIA is used with digital DCEs.'
-
- We tried w/o NRZ and could not get the SYS/36 to 'talk to' the 5294;
- so I followed the manual suggestion; viola, it worked.
-
- PROBLEM: Despite assurances from the user(s) that they are noticing
- nothing; they are now getting on a regular basis (every 15-30min)
-
- SYS6729 C02 on line 2 is experiencing severe degradation.
- (controller 2 on line 2 ....)
- and
- SYS3410 SDLC line 2 line degradation.
-
- This is a point-to-point line, no multi-drop. We have run the analog
- modems again, the modems work with NRZ or NRZI; the messages continue
- to occur with either the modem or T1; hence it must be the NRZ parm.
-
- So, my question; if I can't run NRZI (like all my 3725 lines) - and
- since NRZ seems to be causing these problems; what do I do? Manual
- references indicate line probs or modem probs ... which I believe
- we have proven to NOT be the problem.
-
- Suggestions welcome, other forums also welcome.
-
- Many thanks .. /Mark
-