Modem does not detect RING from Viking DLE-200B Line Simulator.

When using certain Viking line simulators, DLE-200B or DLE-300, we have seen certain products that do not detect the incoming RING. These products do detect an incoming RING on a POTS line. These products include the initial MT5692SMI products and the MT2492SMI products.

The Multi-Tech specification for RING detection is using the frequency from 15Hz to 68Hz and using a DC offset of 35V and above with up to 100V RMS ring. This range covers 99.99% of all real world ring scenarios and there are no approval agencies that we are aware of that use outside of that range. Normal ring offset is usually 37V to 48V DC with a ring voltage less than 100V RMS.

In testing with the Viking DLE-200B line simulator we found that it uses a 28V to 32V DC offset with a 160V peak to peak signal. In our opinion, this puts the ring from the Viking simulator out of range and makes it an abnormal ring.

Possible Solutions:
- If using the MT5692SMI, MT5692SMI-P or MT5692SMI-V, we have an updated version of patch code to address this issue, version 1.01L. This 1.01L version is also contained in the new revision of the MT5692SMI-x.R1 product.

- We have contacted Viking and their recommendation is creating a Viking support case and sending the Line Simulator into Viking for hardware repairs.

- The MT2456SMI, MT5600SMI, MT5656SMI, MT5634SMI and MT9234SMI products DO detect incoming RING on Viking DLE-200B Line Simulator.