Instruction manual

ACU-1000 Operations Manual
Interoperability Now 2-37
Note the default setting of -9 dBm is the maximum allowed into most U.S. and foreign
telephone networks at the subscriber end. Some PBXs may only allow -12 dBm. Ensure
that the line levels are correct for the network being used and do not exceed maximum
allowed levels.
• Cross-connect the HSP handset to the PSTN and place a call from the PSTN to the phone
number of an associate who will help with the setup. Refer to Section 2.17.3.1, Telephone
Line Level. Within the guidelines presented, the line level may be adjusted in 3 dB steps
to present the proper level to your associate at the remote telephone.
• Now listen as the associate speaks and verify that the VOX LED illuminates on the PSTN
even for softly spoken speech. If the VOX doesn’t always trip, raise the telephone RX
Level Boost setting until it does, but no higher. 6 dB of boost is the default setting and a
good place to start.
• Continue the conversation while monitoring the VOX LED. If problems persist with failure
to VOX or if false VOXing due to background noise at the distant phone occurs, adjust the
VOX threshold. There are only two settings, Low & High. The default setting is Low
threshold. If the VOX does not always trip, and the setting is currently at High, lower the
threshold to the Low setting. If the threshold is already set to Low the VOX cannot be
made more sensitive, so instead increase the RX Level Boost. If the VOX sometimes falses
on background noise and the threshold is set to low, move the threshold to the high setting.
Note: The VOX is expected to trip on loud background noises; lower the
threshold only if the VOX is activated for background sounds that are
below the volume of normal speech.
• Now have your associate on the distant phone count from one to twenty at a slow,
conversational rate. The VOX should remain active throughout. If the VOX drops in and
out, raise the VOX hangtime just until this no longer occurs. The default setting is one
second; if the VOX continually drops out between words, increase it to 1.5 seconds or, if
necessary, to two seconds.
• With the HSP handset, talk with a normal conversation level and have your associate verify
that you are being received at an acceptable level. If not, and you are outputting the
maximum legal level to the line contact JPS for further suggestions.
• Interconnecting multiple active PSTNs together on the same net can sometimes cause
hybrid unbalance issues. Please contact JPS for further suggestions and guidance if this is
required as there are complex tradeoffs required.
JPS 24/7 Technical Assistance Phone Number is 1-800-498-3137.
Press 1 for ACU Help.