BT Redcare 5G Classic STU 11 pin Troubleshooting guide

User/Installation Guide
5G STU
LPS 1277: Issue 3
Cert No. 1270a
Cert No. 1270b

Product name BT item code
Redcare 5G Classic STU 11 pin 049926
Redcare 5G Classic STU 8 pin 076352
Redcare 5G Classic STU PLI 062843
Redcare 5G Fire STU 049927
Redcare 5G STU User/Installation Guide
This manual contains information on the BT Redcare 5G STU product range.
It contains more detailed information than that provided in the quick start user guide provided
with the STU.
Description
The 5th Generation Subscribers Terminal Unit (5G STU) is a communicator for signalling alarm signals between a protected
premises and an alarm receiving centre (ARC). The 5G STU uses the extremely reliable BT Redcare network to convey the
messages over a BT Redcare enabled BT analogue PSTN line. Even if an intruder cuts the line and jams the radio signals an
alarm message will still rapidly be sent to the ARC.
The 5G STU is fully compatible with BT’s 21CN network upgrade programme and connects to any BT Redcare enabled
telephone line.
The 5G STU is fully ADSL compliant and does not require an additional ADSL microfilter.
Fig 1. 5G Classic STU
TNV Cover
PL2
Debug Point
PL1
Serial Port
PL3 Sec/Ln PSTN + Earth
Connectors
LK1
Private Wire Link
Main Terminal Block TB1
Mode Key
Set Key
8 Segment
LED’s
Page 1

Pre-Installation Requirements
Before a 5G STU installation can commence, a BT Redcare Service Order must be submitted to BT Redcare by the Alarm
Receiving Centre. This ensures that the appropriate exchange connections have been made and a block terminal 92A has
been provided at the customer’s premises.
Mounting and Safety Statement
The 5G STU is designed for host-independent fitment.
The circuit board area, under the cover, is classed as a Telecommunication Network Voltage (TNV-3) circuit. All other
interconnection points are classed as Safety Extra-Low Voltage (SELV) circuits. It is only necessary for this cover to be
removed during installation of the PSTN wiring. A functional earth connection using CW1044 cable is required to the
terminal block TB5.
The host alarm panel or box into which the 5G STU is installed must provide a RESTRICTED ACCESS LOCATION in
accordance with the requirements of BS EN 60950.
The unit should be mounted inside the alarm panel, or inside a separate powered housing, using the sticky mounting pads
supplied.
For fire alarm panels the enclosure must meet the requirements of EN 54-21 7.3 (eg. IP30 or above) and the supplied
sticker should be applied to the outside of the housing (fig 2). Enclosure requirements for the 5G STU are the same as for
the fire alarm panel itself and must meet EN 54-2. The enclosure must restrict access to installer level 3. The enclosure
must provide the facility to indicate the state of the fault and acknowledge outputs on the
5G fire STU.
Fig 2. For fire installations apply a label to the outside of the STU enclosure.
For security installations the enclosure must meet or exceed the protection requirements of the particular security grade
for the whole installation as per EN 50131-1
Suitable user protection to ensure compliance with BS EN 60950 should be present on the host or its fitted
equipment. A hazardous voltage is one which exceeds 42.4V peak AC. or 60V DC. If you have any doubt, seek advice
from a competent engineer before installing this or other adapters into the host equipment.
EN 54-21:2006
5G FIRE
Page 2

Static Sensitive Devices
Static electricity is present in our everyday lives. A static charge is generated by friction, and whenever two
dissimilar materials are separated. The imbalance of electrons causes a potential difference of many hundreds of volts.
On discharge, a large current flows for a short time.
Many electronic components can be damaged by such static charges. Component failure may not be immediate
or catastrophic. Electro-Static Discharge (ESD) can cause hidden damage to components, which will affect their reliability.
It is recommended that precautions are taken against damage due to static electricity during the installation and
maintenance of the 5G STU. Suitable ESD protection measures include ensuring that you are earthed (via a wrist strap
and a 1M resistor) whenever you handle the unit.
Telephone Line Connections
Connect the 5G STU to the block terminal using standard telephone cable CW1308. Only one 5G STU may be connected
to any one telephone line.
WARNING: the block terminal contains telecommunication network voltages.
Please note that it is important to use the correct method of connecting the STU to the Block Terminal 92A.
The Block Terminal provides an insulation displacement connection (IDC) block for the incoming phone line.
No connections, other than those made by BT, should be made to this IDC block. The STU should be connected to
the screw terminals as shown. The 5G STU is not polarity conscious on its line terminals.
Power Supply
The 5G STU must be connected to a suitable power supply. The installer must ensure that the rating of the power supply
is greater than the combined rating of the 5G STU and any other apparatus drawing power from the power supply.
For use with intruder alarm panels the power supply must meet the requirements of EN 50131-6. For use with Fire
alarm panels the power supply must meet the requirements of EN 54-4 and the 5G STU must be mounted in the same
enclosure as the power supply from which it derives its power.
The 5G STU supply requirements are detailed later in this manual.
Fig 2: Block Terminal 92A
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REN
The Ringer Equivalence Number (REN) for the 5G STU is 1.0. As a guide to the number of apparatus that can be
simultaneously connected to a line, the sum of REN values for each apparatus should not exceed 4.0. A BT provided
telephone is assumed to have a REN value of 1.0 unless otherwise marked. If the 5G STU is used with an MCD, the
combined REN will be 1.5.
Training Courses
BT Redcare offer a free training course for installers of the BT Redcare service. For further information call General
Enquiries Tel: [phone]*.
* Calls are free to this number from BT landlines and BT payphones. However, they are not free to call from mobile phones - the costs will vary between service providers.
5G GSM STU Inputs
The STU has up to 11 screw terminal inputs plus tamper (T) & AC fail (F) for connection to the monitored equipment such
as an alarm panel (3 inputs on the Fire STU). The alarm inputs are triggered by changing their voltage state.
At default a positive voltage applied to the input will trigger an alarm condition. The polarity of the inputs can be
configured using the PP (Pin Polarity) menu.
For fire alarm panels the fire alarm notification output must be connected to the STU input numbered pin 1.
Pin 1 has an associated fire alarm acknowledgement message, received via the relay output labelled RPS.
A+ Terminals
The STU has 4 terminals marked A+. These terminals provide a 10K resistive connection to +V and can be used to trigger
the alarm inputs through relay contacts if required.
Output Relays
Three output relays are provided: Control, Return Path Signalling (RPS), and Line Fault. The use of any, or all, of these
functions is optional. For a basic installation these outputs are not required.
Note: If an output is to be connected to a device which produces transient voltages, such as a bell, the device should be
suppressed using a suitable protection diode.
For fire alarm installations the indication of ‘acknowledgement of fire alarm’ and ‘SPT fault’ messages must be provided by
the fire panel into which the SPT is mounted.
System fault indications which are notified by the 5G Fire line fault output relay ‘LF’ must be latched by the fire panel as
required by EN 54-21.
Control Output Relay (CTRL)
This relay can be switched on or off by the Alarm Receiving Centre (ARC) operator by sending an output ON or output OFF
command to the STU through the BT Redcare network.
The output can typically be used to remotely reset an alarm panel, or to operate other devices such as lights or door
latches at the site.
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Line Fault Output (LF)
The Line Fault Output is used to indicate that the communication path has failed at the protected premises.
The ‘Line Fault’ relay contacts (Normally Open, Common, Normally Closed) are available for connection on TB1.
The maximum current rating of the relay contacts is 1 Amp.
The LF relay will also activate if a pin alarm is not acknowledged by the ARC within 30s, or if the watchdog timer on the
STU activates.
The polarity of the LF relay can be set by configuring the F2 menu. The default state for the LF relay on the fire STU is
relay activated when path normal (F2=0). This ensures the LF relay will also change state on STU power failure. This
setting (F2=0) should also be used with all 5G STU’s.
Return Path Signalling (RPS)
The RPS output is used to indicate, at the protected premises, that the opening/closing signal has been sent to, and
acknowledged by, the Alarm Receiving Centre.
To use the RPS function, at least one of the alarm inputs must be designated as an opening/closing channel (usually
channel 4). The RPS output will activate when an opening or closing signal is detected. It will de-activate when the
opening or closing signal has been acknowledged by the Alarm Receiving Centre. It is allowable to have more than one
input designated as an opening/closing channel, but each must be acknowledged to de-activate the RPS output.
The RPS relay contacts (Normally Open, Common, Normally Closed) are available for connection on terminal block TB1.
To use this option, a warning device such as a piezo bleeper or external strobe light should be connected through these
contacts. The maximum current rating of the relay contacts is 1 Amp.
Fire ACK Output (RPS/ACK)
Fire STU’s with V4.1 S/W or later have the RPS output configured to act as an Acknowledge output to a pin 1 alarm, i.e.
the RPS/ACK relay will operate when an acknowledgement to a pin 1 alarm is received from the ARC, and the RPS/ACK
relay will release when an acknowledgement to a pin 1 reset is received from the ARC. If a pin alarm is sent from the STU
and not acknowledged within 30s then the LF relay will operate. This allows the STU to be wired as follows to meet the
requirements of EN 54 fire regulations.
Page 5

Typical Monitored Fire Alarm Panel Input 1
Configure LF to be normally energised F2 = 0 and use C – NO connection. This ensures a power fail to the STU will be
detected as a fault by the fire panel.
Configure the fire panel input for EN 54 100s Ack input.
As the input pins on the STU do not detect fault conditions, ensure the STU is fitted within the fire panel housing or in a
separate housing that is directly adjacent to the fire panel. This minimises the risk of faults on the interconnecting wiring.
STU Specifications
Pin alarm inputs:
Logic High = +2.5V to +30V
Logic Low = -0.5V to +0.8V
Logic level outputs:
Logic High = 3.0V @ 560µA max
Logic Low = 0.4V @ 280µA max
With respect to the 0V terminal on TB1.
Power rating:
5G Classic 12Vdc +/- 2V 80-100mAlow battery alarm 10.4V +/- 0.5V 60s delay
5G Fire 24Vdc +/- 4V 80-100mAlow battery alarm 20.5V +/- 0.5V 60s delay
Environmental:
Operating ambient temperature +5ºC to +40ºC
Relay contacts:
30V 1A Max
Physical:
Size = 168 x 115 x 36mm
Telephone Line Selection (LK1)
The 5G STU is supplied ready to connect to the Public Switched Telephone Network (LK1 is not fitted). If the 5G STU
is to be connected to a Private Wire (RedDIRECT) a suitable link must be fitted in the position marked LK1 under the TNV
cover. For RedDIRECT PW working the 5G STU must be configured with F3 set to 1.
Note the LK1 link provides 600 ohm line matching for PW working and is only generally used on legacy RedDIRECT
circuits or for test purposes. For normal PSTN connection LK1 is NOT required.
If you have any doubts about the type of telephone line to which the STU is being connected, contact BT Redcare for
advice.
Page 6

5G STU Displays
The current status of the STU is displayed on the 2 X 8 segment displays.
The STU will cycle through the messages in 1 second steps.
AL = This is followed by the ALarm pins that are active (in the Alarm state). 00 if no alarms are active, or the numbers of
the pins outstanding, i.e. 4 = pin 4 outstanding.
NC = Not Commissioned. The STU has yet to receive an UP STU command from the ARC.
5G STU Configuration
The 5G STU is factory supplied with the most common settings for most installations, so generally the unit can be
installed without the need to carry out configuration. However, if changes to the default setting are required they can be
carried out as follows.
Note: The 5G STU must be in the fully de-commissioned state to enter the configuration menu.
To enter the configuration menu press and hold the MODE button for 5 seconds.
PP will be displayed on the display.
The MODE button can be used to step cycle through the main menu as follows:
PP = Pin Polarity
OC= Message Select (Open Close)
iD = Set Hard ID number
PE= Pin Enable
F1 = Function digit 1 (Control Relay)
F2 = Function digit 2 (Line Fault Polarity)
F3 = Function digit 3 (Connection Type)
F4 = Function digit 4 (Line Monitoring Enable)
F5 = Function digit 5 (Serial Parallel)
LD = Load Default (Reset all variables to manufacturers default)
?? = Commit to microprocessor memory.
The SET button is used to enter the sub menu for each function.
Tip: Continually pressing the MODE button will always eventually return to the main menu and to the ?? exit point.
Tip: The main menu can only be exited at the LD or ?? prompts. (see these sections for exiting configuration mode).
Tip: If the state of configuration is unknown then it can be reset to the factory default settings from the LD load
default menu option.
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PP Pin Polarity
Pressing SET at the PP menu option enters the pin polarity sub menu.
At factory default all inputs are set to positive applied triggering.
The input pin polarity can be changed by using the MODE button to step through pins 1 to 11 t & F, and using the SET
button to toggle the input polarity for that pin.
The following display symbols are used to denote positive applied or positive removed triggering.
Once all pins have been configured, the MODE button returns to the main menu
OC Open Close Message Select
Pressing set at the OC menu option enters the Open / Close sub menu.
At factory default all inputs are set to send ALARM / RESET messages, except pin 4 that is set to send OPEN / CLOSE
messages. The message type for each pin can be changed by using the MODE button to step through pins 1 to 11, and
using the SET button to toggle the message type for that pin.
The following display symbols are used to denote the pin message type:
O = Open / Close
A = Alarm reset
Once all pins have been configured, the MODE button returns to the main menu.
iD Hard ID Number
Pressing SET at the iD menu option enters the hard ID sub menu.
At factory default the unit has the last 4 digits of the serial number as its Hard ID.
Tip: The 4 digit Hard ID forms part of the secure encryption key for signalling and there is generally no need to change
this number.
The 4 digit number is Hexadecimal and can be in the range 0001 to FEFF
Should a change be required the following procedure can be used.
When the Hard ID sub menu is entered, the first 2 digits of the current Hard ID are displayed.
A lit dot above the digit denotes the digit that will be changed with each press of the SET button.
The MODE button cycles to the next digit.
After setting the first 2 digits, the last 2 digits are displayed again with a lit dot to denote the digit that will change with
the SET button.
Once all 4 digits have been configured, the MODE button returns to the main menu.
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PE Pin Enable
Pressing SET at the PE menu option enters the Pin Enable sub menu.
At factory default the all inputs are enabled.
Tip: There is generally no requirement to disable inputs, unused inputs can simply be left disconnected.
Should a change be required the following procedure can be used.
The input pins can be changed by using the MODE button to step through pins 1 to 11 t & F, and using the SET button to
toggle the input to Enabled or Disabled for that pin.
The following display symbols are used to denote pin enabled or disabled.
= is enabled
_ is disabled
Once all pins have been configured, the MODE button returns to the main menu.
F1 Function 1 - Control Output Relay
Pressing set at the F1 menu option allows the Function 1 value to be configured.
At factory default the F1 digit is set to 0.
The function 1 (F1) value has the following functionality.
0 = Control output relay NOT energised at power up
1 = Control output relay energised at power up
Once the F1 value has been configured, the MODE button returns to the main menu.
F2 Function 2 - Line Fault Relay
Pressing set at the F2 menu option allows the Function 2 value to be configured.
At factory default the F2 digit is set to 1.
The function 2 (F2) value has the following functionality.
5G Classic STU
0 Line Fault relay de-energised when landline path has failed.
1 Line Fault relay energised when landline path has failed.
Once the F2 value has been configured, the MODE button returns to the main menu.
Page 9