What causes error message "Paging terminal abandoned block transmission"

[swt1]

 Have a Lookout process that has been running for years.Alarm messages are sent out to Nextel phones using the pager device.Today after an alarm - an error message came up "Paging terminal abandoned block transmission".The manual says "alphanumeric only error code". I have no clue what that means. The pager is set up for alphanumeric. What is causing this problem ? Have rebooted the system as well as the computer.Checked all connections and phone lines. Have replaced the modem. No success. I am at a lost and need answers

[Ryan.S]

In Alphanumeric mode, the pager object is using Telocator Alphanumeric Protocol (TAP).

The error message in Lookout means the pager receives <RS> <CR> for the block response. It is defined in the protocol. Have a look at this article, a description of this protocol.

http://www.gsmfavorites.com/documents/sms/tap/

It is said that

"An <RS> <CR> should be sent at this point if the paging central finds any data <ACK> in step 8 to be unacceptable because of content (e.g. an invalid pager number or a message field inap-propriate for the type of pages, etc.) "