DGS 101 - User Manual

TECHNOLOGIES
Technical Sheet
ref C1540 J
GDS 101
SINGLE POINT GAS ALARM
Operation
A fixed single point alarm unit that meets the requirements for continuous economic and reliable monitoring of gas levels in a
wide range of environments from commercial premises through to heavy industrial applications that may require hazardous
area sensing. The GDS101 may be utilised as a standalone unit or as an addressable sensor forming part of the GDS Combi
CANbus addressable network system and therefore offering the features of our most advanced system.
Typical monitor locations are – public buildings, boiler plant rooms, swimming pools, water treatment works, H&V control
systems, manufacturing and process plants.
Installation
CONTROL UNIT: The control unit should be mounted in a position which is
accessible and in the field of vision.
Mains should be from a fused supply.
SENSORS: The positioning of sensors depends upon the type of gas to be
monitored and its density with respect to air.
HEAVY GASES (LPG, Propane, Butane, Refrigerant Gases) – locate at 15
to 20 cm from the floor.
LIGHTER GASES (Methane, Natural Gas, Town Gas) –
locate at 5 to 10cm from the ceiling.
CARBON MONOXIDE – locate at 1.5 metres above floor level.
All equipment should be mounted away from direct heat and in
accordance with its IP rating.
Initial Set–up Procedure
Having terminated all cables switch on the power and wait for the 1 minute
stabilisation period to complete, this is indicated by the power and inhibit
indicator changing from flashing to a steady state, a reduced power mode
feature is activated one hour following any operator activity, this state is
indicated by a screen power reduction of approximately 50%, pressing
any button will return the screen to full display.
The alarm panel may have been supplied without a sensor and a customer
supplied device is to be used, in this case the following adjustments should
be carried out. Adjust jumpers as follows:
For 24DC (+ sig –) 4~20mA sensor devices connect jumpers
J5/11 Position A, J12 Off, J14 link B.
For catalytic sensors (W Y P) J5/11 Position B, J12 On, J14 Link A.
(Caution reset link J14 to position A before connecting the sensor
as damage will occur requiring sensor replacement).
Sensor supply may be measured between the two sensor voltage test pins,
adjust as required using the sensor supply adjustment potentiometer. See
sensor cell supply table.
Test pins TP6/TP7 may be used to check 4~20mA sensor input signals 4mV
= 4mA.
Measuring across TP8/TP9 will allow the 4~20mA output signal to be
checked 4mV = 4mA. Output for pellistor (flammable) can be adjusted
using 4+20mA pots.
Changes to gas type and range can be made by connecting GDS RS232
pod to J3 and using a PC running hyper terminal at 4800 baud.
The Hyper Terminal output screen shows continuous data output/
commands and allows input from the PC keyboard pressing ‘C’ enters
calibration mode, press ‘G’ to change the gas type to match the cell being
used. Note – the range of the new gas has a default value but can be
adjusted by pressing ‘R’.
For catalytic sensors course zero adjustment is achieved by turning the zero
potentiometer (10 turn) until the zero LED just turns off.
Access to the Menu
The GDS101 is supplied with factory set default settings which may be
re-adjusted from the front screen and push buttons:
Press 2 to access the menu followed by 231, menu entry will be at level 5
(Exit), pressing 1 or 3 will enable travel through the sub menus 1–9 and
adjustment of settings, pressing 2 enables access into each sub menu and
on completion pressing 2 will confirm your selection and move to the next
setting.
1. Zero/Span – In clean air Zero display – apply test gas at the peak
reading and adjust the span.
2. Alarm Levels – 3 alarm levels. Pressing 1+3 together will cycle through
rising and falling alarms and latched (L) or unlatched (U) (auto reset)
relays in following order
(
) L, ( ) U, ( ) U, ( ) L. Default setting latched.
3. Alarm Delay – Time to alarm in seconds
(default setting 2 seconds) maximum 255 seconds.
4. Inhibit Alarm – Isolate alarm functions – maintenance and test periods.
Second part of this menu allows YES/NO selection of sounder alert for
alarm A1.
5. Exit Press 2 – Entry and Exit point of menu.
6. L.C.D Brightness – Adjustment of display brightness.
7. L.E.D/Relay Test – Turns indicators and relays ON.
8. Auto Zero – Use only when very low alarm levels are required
(<10% of scale).
9. Sensor Address – Used when connecting to a GDS
Combi system.
A. 4~20mA output adjust (Tox/O
2
only). Pressing 1 or 3 will allow for
output to be adjusted to 4mA and 20mA as measured on test pins 8+9.
B. To set A1 alarm relay to become a global sounder relay with a 10min
time delay after alarm condition ends. Press 1 to active or press 3 to
deactivate.
C. To delay relay deactivation after alarm condition has ceased, press
2 to cycle through alarms A1,A2 and A3. when the required alarm is
displayed press 1 to increase the delay and 3 to decrease the delay.
D. Allows relay A3 to change from alarm relay to valve timer central relay
E. Relay on time, minimum 2 minutes maximum 200 mins.
F. Relay off time, minimum 2 minutes maximum 200 mins.
E: sales@gds-technologies.co.uk T: +44 (0)113 286 0166
GDS TECHNOLOGIES LTD | FUSION POINT | ASH LANE | GARFORTH | LEEDS | LS25 2GA | UK www.gds-technologies.co.uk

Summary

Operation

Installation and Setup

Control Unit Mounting

Mount the control unit in an accessible location within the field of vision.

Sensor Positioning

Position sensors based on gas type and density relative to air.

Initial Set-up Procedure

Describes power-on stabilization, jumper adjustments for sensors, and signal measurement.

Gas Type and Range Configuration

Configure gas type and range via PC using Hyper Terminal at 4800 baud.

Catalytic Sensor Zero Adjustment

Achieve course zero adjustment for catalytic sensors using the zero potentiometer.

Accessing and Configuring the Menu

Menu Navigation

Access menu by pressing 2, navigate submenus 1-9 using 1 or 3, confirm with 2.

Zero and Span Calibration

Calibrate zero in clean air and span using test gas at peak reading.

Alarm Level Settings

Configure 3 alarm levels, cycling through rising/falling and latched/unlatched relays.

Alarm Delay Configuration

Set alarm delay time in seconds, with a maximum of 255 seconds.

Inhibit Alarm Functionality

Isolate alarms for maintenance/test periods and select sounder alert option.

Display and Relay Testing

Adjust LCD brightness, test indicators, and relays.

Auto Zero and Sensor Addressing

Use Auto Zero for low alarm levels and set sensor address for Combi system.

Analog Output Adjustment

Adjust 4-20mA output for Tox/O2 sensors between 4mA and 20mA.

Alarm Relay and Time Delay Settings

Configure A1 relay as global sounder, delay relay deactivation, and set relay on/off times.

Specifications and Environmental Data

Power Supply Versions

Details for Mains (230/115v AC) and DC (24v DC) versions.

Outputs and Connectivity

Information on alarm/fault relays, CANbus, and 4-20mA analogue output.

Indicators and Display

Description of status LEDs (Power, Alarms, Fault) and the alpha-numeric display.

Audible Alarm

Details on gas/fault muting and sound level.

Environmental Conditions

Specifies operating temperature, storage temperature, humidity, and IP rating.

Sensor Cable Requirements

Details on the 3-core screened cable and maximum length.

Overview

1. Function Description
2. Installation
3. Initial Set-up Procedure
4. Access to the Menu
5. Menu Options
6. Important Technical Specifications
7. Sensor Cell Supply Table
8. Maintenance Features

The GDS 101 is a single-point gas alarm designed for continuous, economic, and reliable monitoring of gas levels across various environments, from commercial premises to heavy industrial applications requiring hazardous area sensing. It can function as a standalone unit or integrate into a GDS Combi CANbus addressable network system, leveraging advanced features. Typical applications include public buildings, boiler plant rooms, swimming pools, water treatment works, H&V control systems, and manufacturing and process plants.

Function Description

The device monitors gas levels and triggers alarms based on predefined thresholds. It features three alarm levels (A1, A2, A3), a fault relay, and a 4-20mA analogue output for integration with other systems. The unit can be configured for various gas types, including heavy gases (LPG, Propane, Butane, Refrigerant Gases), lighter gases (Methane, Natural Gas, Town Gas), and Carbon Monoxide.

Installation

The control unit should be mounted in an accessible position within the field of vision, powered by a fused mains supply. Sensor placement is critical and depends on the gas type and its density relative to air:

• Heavy Gases: Locate 15-20 cm from the floor.
• Lighter Gases: Locate 5-10 cm from the ceiling.
• Carbon Monoxide: Locate 1.5 meters above floor level. All equipment must be kept away from direct heat and installed according to its IP rating.

Initial Set-up Procedure

After connecting all cables, power on the unit and wait for a 1-minute stabilization period, indicated by the power and inhibit indicators changing from flashing to a steady state. A reduced power mode activates one hour after operator inactivity, dimming the screen by approximately 50%; pressing any button restores the full display.

If the alarm panel is supplied without a sensor or uses a customer-supplied device, specific jumper adjustments are required:

• For 24DC (+ sig -) 4-20mA sensor devices: Connect jumpers J5/11 Position A, J12 Off, J14 link B.
• For catalytic sensors (WYP): Connect J5/11 Position B, J12 On, J14 Link A.
• Caution: Reset link J14 to position A before connecting the sensor to prevent damage.

Sensor supply can be measured between the two sensor voltage test pins and adjusted using the sensor supply adjustment potentiometer. Test pins TP6/TP7 can check 4-20mA sensor input signals (4mV = 4mA). Measuring across TP8/TP9 allows checking the 4-20mA output signal (4mV = 4mA). Output for pellistor (flammable) can be adjusted using 4-20mA pots.

Gas type and range changes are made by connecting a GDS RS232 pod to J3 and using a PC with hyper terminal at 4800 baud. The Hyper Terminal output displays continuous data, and commands can be input from the PC keyboard. Pressing 'C' enters calibration mode. Press 'G' to change the gas type to match the cell being used. The range of the new gas has a default value but can be adjusted by pressing 'R'. For catalytic sensors, course zero adjustment is achieved by turning the zero potentiometer (10 turn) until the zero LED just turns off.

Access to the Menu

The GDS101 comes with factory default settings, which can be re-adjusted from the front screen using push buttons: Press '2' to access the menu, followed by '231'. The menu entry starts at level 5 (Exit). Pressing '1' or '3' navigates through sub-menus 1-9 and adjusts settings. Pressing '2' accesses each sub-menu and confirms selections, moving to the next setting.

Menu Options:

1. Zero/Span: In clean air, adjust the zero display. Apply test gas at the peak reading and adjust the span.
2. Alarm Levels: Configure three alarm levels. Pressing '1' and '3' together cycles through rising and falling alarms (latched (L) or unlatched (U)). Default setting is latched.
3. Alarm Delay: Set the time (in seconds) before an alarm triggers (default 2 seconds, maximum 255 seconds).
4. Inhibit Alarm: Isolate alarm functions for maintenance and test. This menu also allows YES/NO selection for sounder alert for alarm A1.
5. Exit: Entry and exit point of the menu.
6. LCD Brightness: Adjust the display brightness.
7. LED/Relay Test: Turns indicators and relays ON.
8. Auto Zero: Use only when very low alarm levels are required (<10% of scale).
9. Sensor Address: Used when connecting to a GDS Combi system. A. 4-20mA output adjust (Tox/O2 only): Pressing '1' or '3' adjusts the output to 4mA and 20mA as measured on test pins 8+9. B. Global Sounder Relay: Set A1 alarm relay to become a global sounder relay with a 10-minute time delay after the alarm condition ends. Press '1' to activate or '3' to deactivate. C. Delay Relay Deactivation: Delay relay deactivation after the alarm condition has ceased. Press '2' to cycle through alarms A1, A2, and A3. When the required alarm is displayed, press '1' to increase the delay and '3' to decrease it. D. Valve Timer Central Relay: Allows relay A3 to change from an alarm relay to a valve timer central relay. E. Relay on time: Minimum 2 minutes, maximum 200 minutes. F. Relay off time: Minimum 2 minutes, maximum 200 minutes.

Important Technical Specifications

• Mains Version: 230/115V AC 50/60 Hz
• DC Version: 24V DC ± 15%
• Power: 4W
• Outputs:
  • Alarms 1, 2, 3 relays – S.P.C.O. ND (NE option)
  • Fault Relay – S.P.C.O. ND (NE option)
  • Normally latched (unlatched option)
  • Relay contacts rated 3A/230V AC
  • CANbus – see Combi alarm system
  • 4-20mA analogue output
• Audible Alarm: Gas/Fault mutable: 85dB@10cm
• Environmental:
  • Operating temperature: 15 to +50°C
  • Storage temperature: 5 to +55°C
  • Humidity: 5-95% RH non-condensing
  • Protection: IP65
• Sensor Cable: 3 core 1.5mm screened → 1.5km
• Indicators:
  • Power: Green L.E.D
  • Alarms: 1, 2, 3 Red L.E.D's
  • Fault: Amber L.E.D
  • Display: 2 line alpha-numeric

Sensor Cell Supply Table

The device supports various sensor types with specific voltage and current requirements:

• CAT300A: 2V/300mA
• CAT170A: 2V/175mA
• SEM-1: 5V/170mA
• SEM-1 (Ammonia): 4V/170mA
• GDS PRIME: 4V/70mA
• F6-170: 2V/175mA
• CAT335C: 2.5V/335mA
• THE300A: 2V/300mA
• SS10: 2V/175mA
• CAT335A: 2.5V/335mA
• CAT335B: 2.5V/335mA
• CAT100A: 2V/100mA

Maintenance Features

• Inhibit Alarm: Allows isolation of alarm functions for maintenance and testing periods without triggering false alarms.
• LED/Relay Test: Provides a quick way to check the functionality of indicators and relays.
• Zero/Span Adjustment: Enables recalibration of the sensor for accurate readings in clean air and with test gas.
• Hyper Terminal Access: Facilitates advanced configuration and troubleshooting via a PC connection, allowing changes to gas type, range, and calibration.

DGS 101 Specifications

General

Brand	DGS
Model	101
Category	Security System
Language	English