The MDR-2000 is an Intelligent Storage Unit, a compact, microprocessor-based data collection device designed for maintenance-free operation with high reliability and data integrity. It primarily collects Call Detail Record (CDR) data and optionally image data from Private Branch Exchanges (PBXs) for later transmission and downstream processing.

Function Description:

The core function of the MDR-2000 is to collect CDR data from PBXs and format it into an Expanded MDR Standard Record format. This standardization simplifies downstream processing by presenting records from different PBX types in a consistent format. The device also supports the collection of maintenance records and can be configured to report alarms or error conditions to a downstream processing facility.

During the formatting process, call records can be filtered based on criteria such as the number of digits dialed, call duration, and whether the call is incoming or internal. This allows for the discarding of incomplete or local calls and fine-tuning of collected data. The MDR-2000 can also deduct a selected duration from the reported call time to eliminate circuit connection and ringing delays, improving downstream processing accuracy.

The MDR-2000 communicates with the PBX via an RS232-C compatible port, typically configured for a standalone hardcopy terminal. Communication with downstream processing facilities is also via an RS232-C port, either through a direct connection or a modem.

Important Technical Specifications:

CPU: Z80 CPU based system.
Memory: 64K bytes of processor memory (RAM) and 128K to 8MB of buffer memory.
ROM: Provision for a 128K-bit ROM, which overlays the first 16K of processor memory.
Serial Ports: Two RS232-C serial ports, each capable of transmitting and receiving at speeds from 300 Baud to 19200 Baud.
Data Transmission: Asynchronous data transmission, programmed for 8 data bits, no parity, and 1 stop bit. It receives 8 data bits, with the high-order bit removed under software control for specific cases.
Power: Requires a single 110VAC outlet.
Battery Backup: Sufficient battery capacity for approximately 60 minutes of operation during power disruptions.
Physical: Housed in a single cabinet, requiring no cooling fans or external climate control beyond a normal office or communications room environment.

Usage Features:

The MDR-2000 operates as a "slave" device, meaning it collects data from the PBX but does not initiate communications with it. It responds to commands from a downstream data collection processor to send preprocessed records and does not initiate data transmission, except in its role as an Alarm Annunciator.

Data Integrity: To ensure data integrity during transmission to the downstream processing unit, data is encapsulated in a data packet containing byte count and checksum information for error detection. If an error is detected, the MDR-2000 is requested to resend the packet. The device also incorporates hardware and software to isolate internal data integrity violations, interrogating stored data upon transmission to ensure it remains unaltered.

Command Structures: The MDR-2000 supports two command structures:

Computer-to-Computer Commands: These are simple, two-character commands preceded by a SYN character (ASCII 16H) and terminated by a carriage-return (ASCII 0DH). They are designed for automatic data collection and remote diagnosis. Examples include:
- BE (Begin): Moves buffer pointers to the beginning of the current data storage buffer.
- CA (Collect All): Transmits both CDR and Image data sequentially.
- CC (Collect CDR): Transmits only CDR data.
- CI (Collect Image): Transmits only Image data.
- CL (Clear): Erases data from the beginning up to the current buffer pointer.
- DB (Door Bell): Returns a 'Hello' response to confirm connection.
- DU (Dump): Outputs all raw data received on the PBX port to the modem port.
- FD (Formatted Dump): Outputs formatted CDR records automatically.
- ID (Identification): Outputs information about the MDR-2000 (PBX generic, software revision, serial number, copyright notice).
- IM (Interactive Monitor): Invokes the Interactive Monitor.
- MR (Master Reset): Resets the entire system, causing data loss.
- OK: Advances the buffer pointer to the next logical record.
- RB (Repeat Block): Retransmits a block of records (used with XB).
- RN (Reset NVR): Initializes non-volatile RAM to factory settings.
- RP (Reset Port): Initializes the PBX port.
- SD (Stop Dump): Cancels the DU command.
- SM (Send Maintenance): Transmits an MDR-2000 maintenance record.
- TE (Test): Dumps a single line of test characters.
- VW (View): Displays the last invalid record received.
- XB (Transfer Block): Sends a block of records.
- XT (Transmit): Sends the record at the current buffer pointer.
- 19: Temporarily sets modem and PBX port baud rates to 19200.
Interactive Monitor Commands: This software module provides a more human-engineered interface for operational control, setup, and remote diagnosis. It offers most of the functionality of the computer-to-computer commands but in a user-friendly format. Commands are echoed, and arguments can be numeric, ASCII, or MDR BCD. Examples include:
- ADVANCE: Advances the current record pointer.
- ALARM TABLE: Enters and modifies the alarm condition table.
- BEGIN: Moves the record pointer to the first logical record.
- CLEAR: Resets Logical Error Count and I/O Interrupt Status.
- CUSTOMIZE: Enters field settings and PBX customization options.
- DIGITS TABLE: Enters and modifies the call exception table.
- DUMP <Addr> <Repeat>: Prints memory contents.
- HELP: Displays available commands.
- IDENT: Prints MDR-2000 identification message.
- MODE: Sets DUMP and PUT command value arguments mode (hexadecimal, ASCII, MDR BCD).
- OPEN LINK: Permits two-way communications from modem to PBX port, acting as a direct cable.
- PUT <Addr> <Value> ... <Value>: Puts string contents at a specified address.
- QUIT: Exits the Interactive Monitor.
- RAM: Sets the physical RAM for memory addresses (processor or buffer).
- READ: Outputs the current record.
- SET <Keyword>: Sets various parameters (e.g., SET ALARM, SET BAUD, SET BYTE SIZE, SET CDR, SET DATE, SET DESCRETE COLLECTION FUNCTIONS, SET DIGITS, SET DURATION, SET EXT->EXT, SET IDLE PBX, SET IMAGE, SET INCOMING, SET METER, SET MULTI, SET NAME, SET OPTIONS, SET PARITY, SET PORT RESET, SET PRIMARY PHONE, SET RETRIES, SET SECONDARY PHONE, SET TANDEM, SET THRESHOLD, SET TIME, SET SITE, SET XFER BLOCK).
- SHOW <Keyword>: Outputs information based on a specific keyword (e.g., SHOW ALARM, SHOW AUTODIAL, SHOW DIGITS, SHOW IDENT, SHOW MAINT, SHOW PORT, SHOW STATUS).
- STATUS: Outputs a comprehensive display of MDR-2000 parameters.
- TEST <Keyword>: Runs nondestructive hardware tests (e.g., TEST LOGICAL, TEST NVR, TEST PORT, TEST RAM).
- VIEW: Outputs the last rejected record.

Alarm Annunciation: When enabled, the MDR-2000 scans image records against an Alarm Table. If a match occurs and a repeat count reaches zero, an alarm is raised. The MDR-2000 then dials a Hayes compatible modem using pre-stored primary and secondary phone numbers to dump an alarm message. The alarm message includes record type, date, time, serial number, site number, site name, alarm code, and description. The system retries autodialing up to a specified number of times if the line is busy or an error is detected.

External Alarm Generation: Certain MDR-2000 models with 24 external jumpers ('A' through 'X') can detect changes in jumper conditions, generating an alarm with a condition code like 'M2KEXT:'.

Internal Alarm Generation: The MDR-2000 reports internally generated alarms for conditions such as:

M2KTHR: Storage Threshold Exceeded (buffer full alarm).
M2KIDL: PBX Idle Time Threshold Exceeded (no PBX output within a specified interval).
M2KPBD: Possible Battery Depletion (for specially equipped units).
M2KCCD: Contact Closure Detected (for specially equipped units).

Modem Setup: The modem connected to the MDR-2000 must be asynchronous, support the standard 'AT' command set (Hayes compatible), and be configured for 'Full Word' or 'Verbal' responses. Character echo to 'AT' commands must be suppressed, and the modem must be set to auto-answer mode (e.g., ATS0=1). These settings are saved using AT&W.

Discrete Polling: This feature allows a host system to selectively collect either CDR data or image data. When enabled, commands like CC (Collect CDR) or CI (Collect Image) are used to specify the data type. The CL command is used to clear the buffer and reposition pointers for collecting the other data type.

Large Blocksize Polling: For improved data transmission rates, the MDR-2000 can transmit data in blocks larger than one record, configured via the SET XFER BLOCK command (1 to 255 records). The XB (Transfer Block) and RB (Repeat Block) commands are used for this.

Maintenance Features:

LED Indicators: Eight LED indicators (CR2 through CR9) provide immediate diagnostic and operational feedback.
- MSD (CR2, ON): Modem port transmitting to host.
- MRD (CR3, ON): Host system transmitting to modem port.
- ERR (CR4, ON): MDR-2000 hardware error has occurred.
- PBX (CR5, ON): PBX transmitting to PBX port.
- BMT (CR6, ON/OFF): ON indicates buffer empty; OFF indicates buffer not empty, calls being stored.
- BFL (CR7, ON/Flashing/OFF): ON indicates buffer full, calls discarded; Flashing indicates preset threshold reached; OFF indicates buffer not full.
- INT (CR8, ON): MDR-2000 processing a hardware interrupt.
- RUN (CR9, ON/OFF): ON indicates running in non-interrupt mode; OFF indicates not operational.
- All LEDs ON simultaneously indicate the initialization sequence.
Troubleshooting: The manual provides guidance on troubleshooting common problems related to the PBX, cables, modems, transmission equipment, or the MDR-2000 itself. This includes checking cable connections, PBX output, communication port settings, and data transparency of the link.
Interactive Monitor for Diagnosis: The Interactive Monitor allows technicians to remotely diagnose problems, verify settings, and perform tests.
- IDENT command confirms the installed PBX generic and software revision.
- STATUS command displays current operational parameters, including records stored, port configuration, and data collection settings.
- SHOW MAINT displays maintenance data for diagnostic purposes.
- TEST commands (TEST LOGICAL, TEST NVR, TEST PORT, TEST RAM) perform nondestructive tests to check hardware integrity.
Error Handling: The MDR-2000 has diagnostic features to aid in problem determination. Keep-alive circuitry and battery backup ensure continued operation during power failures. The ERR LED (CR4) indicates hardware errors or memory errors during data transmission.
Reporting Problems: When reporting issues to MDR, specific information is requested, including EPROM revision, status information, serial number, PBX model and software settings, Customize command output, a sample of CDR output, Test command results, and details on modems/multiplexors used.

MDR MDR-2000 - Page 73