ASCOM T942C - User Manual

TD 91684GB
16 April 2015 / Ver. G
Installation Guide
T942C and T942C/2 Central Unit

Summary

Central Unit T942 C

Regulatory Compliance Statements (EU;EFTA only)

Declares compliance with EU/EFTA EMC directive 2004/108/EC.

Regulatory Compliance Statements (USA only)

FCC compliance statements for digital device, outlining interference prevention measures.

T942 C Board Description

Detailed overview of the T942C circuit board components, connectors, switches, and LEDs.

T942 C Installation Procedures

Step-by-step guide for installing the T942C Central Unit, including mounting and wiring.

Mounting the T942 C Unit

Instructions for physically mounting the T942C unit to a solid vertical wall.

Opening the T942 C Housing

Procedures for safely opening the Central Unit's housing for access.

Mounting T942 C with Other Units

Guidance on how to mount the T942C unit in conjunction with other system modules.

T942 C Wiring Runs

Methods for routing cables and wiring from the Central Unit enclosure.

T942 C Addressing on C-bus

How to assign a hexadecimal address to the T942C on the C-bus using SW01.

Connecting T942 C Buses

Details on connecting system buses via modular cabling or twisted-pairs.

Connecting T942 C Supply Voltage

Instructions for connecting the power supply to the T942C unit via connector J03.

Connecting Reference Module in FL-System

Connecting the Reference Module T938RM to the Central Unit for paging systems.

Connecting T942 C Monitor Input

How to connect a monitor source to the Central Unit for transmitter control.

Connecting PC to T942 C

Guide for connecting a PC to the T942C for communication and configuration.

T942 C Relay Output for System Fault

Using the relay output on J10 for indicating system faults or Central Unit malfunctions.

T942 C Malfunction Output

Using output 3 on J12 to specifically indicate Central Unit malfunction.

Activating T942 C Power Changeover

How to activate the RAM back-up battery using jumper S03.

T942 C Installation Test Procedure

Steps to verify the correct installation and operation of the T942C Central Unit.

T942 C Circuit Board Replacement

Detailed instructions for safely replacing the internal circuit board of the T942C.

Central Unit T942 C;2

General Information on T942 C;2

Introduction to the T942C/2 Central Unit, its purpose, and key features.

T942 C;2 Regulatory Compliance

Refers to T942C compliance statements for the T942C/2 unit.

T942 C;2 Board Description

Overview of the T942C/2 circuit board components, connectors, and LEDs.

T942 C;2 Installation Guide

Guide for installing the T942C/2 Central Unit, covering mounting, wiring, and connections.

Mounting the T942 C;2 Unit

Instructions for physically mounting the T942C/2 unit.

Opening the T942 C;2 Housing

Procedures for safely opening the T942C/2 housing for access.

Mounting T942 C;2 with Other Units

Guidance on mounting the T942C/2 unit with other system modules.

T942 C;2 Wiring Runs

Methods for routing cables and wiring from the T942C/2 enclosure.

Connecting T942 C;2 Buses

Details on connecting system buses for the T942C/2 unit.

Connecting T942 C;2 Supply Voltage

Instructions for connecting the power supply to the T942C/2 unit.

Installing T942 C;2 Software

Procedure for installing software onto the T942C/2 FLASH PROMs.

T942 C;2 Installation Test Procedure

Steps to verify the correct installation and operation of the T942C/2 Central Unit.

T942 C;2 Circuit Board Replacement

Refers to the T942C circuit board replacement procedure.

Programming T942 C Central Unit

Preparations in PDM for Programming

Steps to configure the Portable Device Manager (PDM) for connecting to the Central Unit.

Central Unit Configuration

Describes how to set parameters using definition files (.def) and PDM.

Setting the License for T942 C

Instructions for setting a valid license on the Central Unit via PDM.

Document History

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

The T942C and T942C/2 Central Units are integral components of the Ascom Paging System, designed to manage all communication across the system and data buses. These units are responsible for generating code for H/U952T Terminal Transmitters and facilitating parallel operation of separate installations. To ensure robust performance and compliance, all inputs and outputs are equipped with transient protection, and all bus connections feature chokes for enhanced EMC protection. The T942C/2 is a simplified version of the T942C, intended for use in smaller Ascom Paging Systems.

Function Description:

The primary function of the Central Unit is to control and coordinate all communication within the paging system. This includes managing data flow on the system bus and various data buses, as well as generating the necessary codes for terminal transmitters. The unit's design emphasizes reliability and electromagnetic compatibility (EMC) through its protective features.

Important Technical Specifications:

• Supply Voltage: Both the T942C and T942C/2 operate on a 12.5 V DC supply, with a tolerance of ± 10%.
• Current Consumption: The maximum current consumption for both units is 1 A.
• Power Cable Protection: It is crucial to protect the unit against currents exceeding 20 A. Power cables with a cross-section of 3 mm² are recommended for this purpose.
• EMC Compliance: For specific revisions (541293A, rev. 3A or later, and T942C2, rev. 2A or later), ferrite beads must be mounted on all cables to meet EMC regulatory requirements.
• Operating Environment: The units should be placed in a dry environment with a temperature range of 0 to +40°C.
• Connectors:
  • J01, J02: Modular jacks for system bus cabling.
  • J03: Supply voltage connection.
  • J04: For A, C, or D-bus connection via twisted-pair wiring when modular bus cabling is not feasible.
  • J08: Modular jack for A-bus connection.
  • J09: Modular jack for PC-line connection (direct or via modem) for RS232C communication.
  • J10: Relay output for system fault indication and Central Unit malfunction indication.
  • J11: Connector for 4 external digital 12 V DC inputs (Input 1 for monitor receiver H/U989M).
  • J12: Connector for 4 external digital outputs (12 V DC, open collector type). Output 1 for Reference Module T938RM in paging systems, Output 2 for H/U952T Terminal Transmitter transmission indication, Output 3 for Central Unit malfunction indication.
  • J14: Modular jack for D, C, and DR-buses, and AUX RELAY.
• IC-Circuits:
  • IC01: Microprocessor (type 80C188EB).
  • IC08: Module key.
  • IC13, IC14 (T942C only): FLASH PROMs containing software for the main processor.
  • IC22: RAM memory with battery backup.
  • IC54: FLASH PROM containing software for the communication processor.
• RAM Backup Battery: A 3V lithium battery provides backup for the RAM and real-time clock during power interruptions.
  • Current Consumption (RAM and real-time clock): Typical 2 µA, max 40 µA.
  • Battery Life (5V not connected): Typical 7 years, min. 0.5 years.
  • Battery Life (5V connected): Minimum 10 years.
  • Battery Life (battery not connected): Min. 10 years.

Usage Features:

• Mounting: The unit must be mounted by trained personnel to a solid vertical wall with the bottom facing the floor. Dimensions are 275 x 130 x 60 mm. A free space of approximately 150 mm above and 50 mm below the unit is recommended for service.
• Housing Access: The housing cover can be released by applying light pressure to two snap catches. For mounting without sufficient space below, cut-out holes in the housing lid can be opened to facilitate maintenance access.
• Wiring Runs: Cabling can be routed through rectangular covers on the side, round holes at the back, or circular covers at the top of the side case. Scored plastic partitions are provided for easy breaking to create suitable openings.
• Addressing: The T942C's address on the C-bus is set hexadecimally using address switch SW01. Units on the C-bus must be assigned addresses in ascending order starting with 00.
• Bus Connection: Buses can be connected using modular bus cabling or twisted-pairs. Data buses are polarized, and only twisted-pairs should be used for two-wire connections.
• Supply Voltage Connection: The supply voltage is connected to J03. An FP5 Fuse board 1.25A (very-fast acting) must be added between J03 and the screw terminal. Digital inputs and outputs (J11/J12) require supply voltage; galvanic isolation can be achieved by using a separate power supply for J11/J12.
• Reference Module Connection (Paging Systems): For FL-Systems, a twisted-pair connects J12 (screws 6 and 2) to Reference Module T938RM J04 (screws 5 and 6).
• Monitor Input: A monitor input (J11, screws 1 and 2) can prevent H/U952T Terminal Transmitters from transmitting when a carrier wave is present, thus preventing the Central Unit from activating output stages or sending transmitter codes.
• PC Connection: The serial communication port on a PC can be connected to J09 on the T942C, either directly or via modems, using 9-pin or 25-pin D-sub connectors.
• Relay Output for System Fault Indication: J10 provides a relay output for system fault and Central Unit malfunction indication. The relay is actuated when the system operates properly. If deactuated for more than 20 seconds, it indicates a malfunction.
• Central Unit Malfunction Output: Output 3 on J12 (screw 4) can specifically indicate Central Unit malfunction, with a maximum output capacity of 100 mA (open collector type).
• Power Changeover Circuit Activation: The RAM backup battery is activated by closing jumper S03 on the circuit board.
• Programming (T942C only): The T942C is programmed using the Portable Device Manager (PDM) software application on a computer. This allows system administrators to customize parameters and functions.

Maintenance Features:

• Installation Test Procedure: A detailed procedure is provided to verify proper system operation, including checking switch settings (SW02, SW01), jumper settings (S03, S17A, S17B, S10A), and module key (IC08) installation.
• Function Indicator (LED01): This LED provides visual feedback on the unit's status:
  • Red (1 second), then flashing orange: Initial power-up and self-test.
  • Short blinks (orange, 1-second intervals): Self-test in progress, parameter list copied.
  • Rapid blinks (orange, 5 times/second): Survey of modules on data buses.
  • Steady orange: Normal operation.
  • Steady red: Supply voltage issue (12.5 V DC ± 10% check required).
  • Flashing red (100 ms ON, 800 ms OFF): Incorrect software license.
  • Flashing green (800 ms ON, 100 ms OFF): Parameter fault.
  • Flashing red (1 s ON, 1 s OFF): Watchdog reset.
• Circuit Board Replacement: Instructions are provided for safely replacing the circuit board, including disconnecting power, removing the cover, detaching connectors, releasing holding clips, installing the new board, setting switches and jumpers, reinstalling software, and performing an installation test.
• Software Updates: FLASH PROMs containing software for the main and communication processors can be pressed onto IC-sockets IC13 and IC54, respectively, for software updates.
• Parameter Configuration: Parameters are configured using PDM, allowing for customization of the Central Unit's functionality. This includes setting COM port preferences, baud rate, parity bit, and password.
• License Management: A valid license is required to set parameters. The process involves setting SW02 section 5 to ON (unlicensing mode), restarting the unit, connecting to PDM, entering the license, and then setting SW02 section 5 to OFF and rebooting for normal mode.

ASCOM T942C Specifications