You are here: CSP Developer’s Guide: Overview > 7 Configuring and Using Resources on the DSP Series 2 Cards > Digit Collection
DSP Service Request
Use this message to allocate an appropriate digit receiver and attache it to the specified channel. The attached digit receiver uses the Call Processing Event 0x002E message to report digits as they are decoded, one at a time. The receiver remains attached to the channel until the channel is released or until the host cancels digit collection, with the DSP Service Cancel (0x00BE) message.
Use this message to allocate and attache a digit receiver to a channel. Unlike the DSP Service Request message, this message causes the CSP to collect a group of digits in sequence until termination condition occurs. The termination condition could be the detection of a particular digit from a termination digit set, a fixed number of digits collected, or a timeout.
Digit Collection After Call Setup
After a call is set up, the CSP collects DTMF digits interactively. The host collects additional information, either one digit at a time with the DSP Service Request message, or as a sequenced group of digits with the Collect Digit String message.
Collecting Inpulse Data on Specified Channels
Use the Inpulsing Parameters Configure message. Inpulsing parameters define the address signaling type, the number of digit strings, and the collection method used during call setup.
The CSP supports four different inpulsing stages, each with one or two digit strings. When the host is instructing the CSP to collect address signaling information (that is typically presented with in-band dual frequency tones) it also specifies a preprogrammed inpulsing stage that describes how to perform the digit collection.
The inpulsing stage configuration options include the following:
• Address signaling type (DTMF, MFR1, MFR2)
• Number of strings (1 or 2)
• String collection method (fixed number digits, KP/ST framed, compelled)
Receiving Address Signaling Tones
Use the The Inseize Control message passes inseize instructions to the CSP for controlling incoming call setup in real time. The instruction, "Receive Stage N Address Data" allocates and attaches a DSP resource to a channel to collect an incoming digit stream.
Up to 100 digits can be collected within a given inpulsing stage. Use the Inseize Instruction List Configure (0x0029) message to preprogram instructions on a channel. See "Digit Collection During Call Setup" for more information. The instruction, Report Incoming Call With Address Digits, sends a Request For Service With Data (0x002D) message to the host, with single- or multiple-stage digit streams collected.
When the termination condition occurs, the CSP reports the entire group of digits collected, with the Call Processing Event 0x002E message. The receiver is then returned to the system receiver pool. If the configuration bit 4 is not set (or "by default") when the CSP detects the first valid digit, it automatically cancels any prompting tone or recorded announcement being played out to that channel.