Mercury SRBX Polling

MI Modem

When an alarm occurs in the Mercury modem, the modem will call the host computer.

After detecting the call-in, ACM will:

1. Accept the phone call (if the host modem is configured to Auto Answer).
2. Request the Mercury device to identify itself.
3. Clear the alarm.
4. Poll for items and historical data.

The detection of a call-in is a two-step process. After the call-in is detected, ACM must identify the Mercury device that initiated the call by sending a poll request. The modem connection must be maintained to complete these steps successfully. This requires the use of a Hang Up delay in the Modem setup for the port assigned to the Mercury devices. Just a few seconds should be sufficient.

To make ACM poll data during a call-in, create a dummy Mercury device to accept the initial call-in.

This dummy Mercury device will have to:

1. Contain “DummyCallin” as part of its name.
2. Have MI modem option checked on device page.
3. Have Perform demand poll during a call-in option checked on device page.
4. Have a unique site ID 1 and site ID 2.
5. Have a unique modem port ID.
6. Have a standard item advised in OPC client (EX: CRC).
7. Have the Support Unsolicited Messages option checked on polling page.
8. Have a polling interval set to 00:00:00.000.
9. Have a connection setup on connection page.

Messenger Modem

When an alarm occurs in the Mercury device, the device will call the host computer.
After detecting the call-in, ACM will:

1. Accept the phone call and identify the device base on the site ID 1 and site ID 2 in call-in message;
2. Poll for items and historical data.

The detection of a call-in is a two-step process. ACM will identify the Mercury device that initiated the call. The modem connection must be maintained to complete these steps successfully. This requires the use of a Hang Up delay in the Modem setup for the port assigned to the Mercury devices. Just a few seconds should be sufficient.