EDR detection (either CNG or DTMF tones) will be disabled once detection occurs. However, a customer’s program might not answer because the setting of the software may require multiple rings to answer. S51 bits
The timing relationship between the Caller ID (if enabled), EDR, and ring detection is as follows:
ring1 | ring2 |
| ring3 |
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| ||
*** |
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| 3sec | 3s | 3s | 3s | S7 |
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+ |
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CID/EDR RD | EDR | RD | EDR RD | EDR | RD | ||
CID=Caller ID task RD=Ring Detection task | EDR=EDR task |
ONOTE: DURING THE EDR PERIOD, ANY AT COMMAND WILL DISABLE THE EDR FUNCTION.
EDR Application Example
If we use ZFAX as our fax receiving application and we don’t want it to answer the call unless it is a fax call, the way to set it up would be:
1.Set ZFAX to answer on 2 rings.
2.Set S51.0=1 to enable EDR and report RING twice. The modem will not report a normal RING and ZFAX will not answer a call unless EDR RING is reported.
3.Set S51.4=1 to enable fax CNG tone detection. It is reported as RING.