Fluke Process Instruments

This quick guide discusses the functionality provided by the Tailgate Detection Register.

Note that Tailgate detection is an advanced analytical function which utilises the USB IO module in the vast majority of applications. This is because the vast majority of access control systems will require interfacing via relay inputs and outputs. Because of this it is not available in Vector Count devices, and because the non-PoE variant Vector does not support the USB IO module, it is only supported on PoE enabled Analytic Vector variants.

This document should be used in conjunction with Tailgate Installation Guide which details the specific wiring connection details, and the standard Vector installation guide docs.

Pre-requisites

The Vector must be installed and powered, with the USB-IO module correctly connected to the Vectors USB connector.

It is strongly recommended that all devices are running the very latest available version of firmware before proceeding.

Some networking knowledge is required to make the initial setup connection to your Vector for configuration purposes.

A working knowledge of the interfacing requirements of your particular access control system is also required - only you will know this information.

Vector Connection

Although the majority of access control systems are relay/pulse/contact based, Vectors are modern IoT devices primarily communicating via IP. To configure the Vector, you can install the RIFT setup tool software exe, or open a web browser and connect via it’s built in web-based setup tool. See Irisys Vector 4D - Making a Setup Connection for more details.

Preliminary height information should be entered before continuing. Ensure the correct mounting height is entered – simply enabling ‘Auto height’ in device settings is strongly recommended.

Instructions

1. Valid Card Signal configuration.

The first thing to configure is the relay input on the USB-IO module that provides the connection to the access control systems ‘valid card signal’ pulse.

First make sure that your USB-IO module is connected to the Vector, indicated by the presence of the ‘Relays’ tab under ‘Settings’.

Enable the input register relating to the one physically wired to the access control systems ‘valid card’ signal line.

Give it a suitable name.

Make sure you click the ‘Save Changes’ button before navigating away from this page.

Before proceeding, test that the register does indeed increment every time you present a valid card. See 'Testing' below for more details.

2. Adding the Tailgate Register

Click on the ‘Counting’ tab to access the main Vector counting functionality.

By default, a Vector will have two counting lines configured, plus a register associated with the newly configured relay input, as shown in the Register dialog list below. If the registers dialog is not shown, click the ‘Registers’ button in the top right:

To add a Tailgate register, click the plus symbol (+) on the Register dialog window:
Then choose the ‘Tailgate’ type register from the list of available types. Once highlighted, click the ‘Next’ button:
First, give the register a suitable name, and click ‘Next’:
Set the ‘Access Event Register’ to the input register configured earlier. Ensure there is only one check box ticked in this section:
Set the ‘Entry Counting Register’ to a standard count line. Again, ensure that only one checkbox is ticked:
Set the ‘Timeout’ value to a suitable value in seconds: The timeout value is used to ignore a valid card input after a certain time. In this way, if someone presents their card but then changes their mind and does not proceed through the secure door, an unauthorised person cannot enter in their place. Any entries after the timeout has elapsed will cause a tailgate alarm. Note this value must allow sufficient time for authorised people to enter. Pay particular attention to any additional disabled access requirements. Click ‘Next’.
Then click the ‘Add Register’ button.

3. Configure the Tailgate Alarm Relay Output

Go back to the ‘Relay’ configuration tab and assign the ‘Tailgate Alarm’ register just added, to one of the Relay outputs.

This output signal is the one that the access controller will use to drive further events – such as enabling CCTV recording, locking a subsequent door, sounding a buzzer etc. so make sure it is the one physically wired to the access control system.

Select the “Tailgate Alarm” register (or whatever you called it) from the drop-down list of Registers.

The relay ‘Mode’ should be set to ‘Pulse’, with an appropriate ‘Pulse Width’ duration for your access controllers input requirements.

If a very long duration pulse is required which is greater than the maximum pulse duration value allowed here, use this output to drive a second latching relay instead.

Make sure you click the ‘Save changes’ button before navigating away from this page.

4. Optional – Deleting Surplus Count Line

For the Tailgate functionality, you only need one count line register, so optionally, any other count lines can be deleted. Note that leaving unused Line(s)/Register(s) will not interfere with Tailgate functionality, which is why this step is optional.

To delete a register, click the ‘Edit Register’ button on the Registers dialog window:

Then click the Delete button:

5. Count Mode Configuration

The main count line needs to be in the correct count mode. To change/verify the count mode, click the ‘Edit’ button for that line.

Then change the Count Mode to the ‘Immediate’ mode and ensure that ‘Anti Dither’ is enabled.

Note that the alternative ‘Deferred’ count modes options are not recommended for Tailgate detection applications.

Click ‘Save Register’ before closing this dialog window.

6. Position the main Count Line

The main count line will now increment as soon as a person crosses it. It must be configured in the correct place in the field of view to ensure that anyone who goes through the secure door has to cross the line. They should not be able to enter and go around the line. To do this, first go into ‘Edit Mode’:

The line can now be moved and positioned as required. Clicking and dragging on a straight part of the line will move the whole line; clicking and dragging on one of the ‘pivot’ points will move just that point.

Line Positioning Hints

1. Ensure that the line is counting in the correct direction (through the door) as indicated by the arrow directions on each line point. ‘Flip’ the line if required.
2. Place the line away from the movement of the secure door itself. Line should be positioned just outside the swing of any door, usually in an arc around the door. Note that the line can be positioned in lots of different ways. See here for more details of line placement.
3. Switch between ‘Edit Mode’ and ‘Video Mode’ in order to see the impact of your line position changes.
4. Walk in and out through the door, making any required changes until you are happy with the counting performance. The register associated with the line should increment correctly for each entry through the door, but the movement of the door should not generate any count increments.  

The above settings should provide a robust tailgate detection system, but Irisys recommends sufficient walk testing to ensure that you are happy with the performance.

Advanced Settings

Lower and Upper Limits

As part of the relay input configuration in step 1 (above), you can also configure specific Upper and Lower bounds for the input pulse width. This may be required if there is noise or other interference on the input line, which would be indicated by the Valid Card register increasing by more than one when a single card is presented.

To set min and max values click the ‘cog’ symbol next to the input setting:

Lower and/or Upper limits can be set as required, by ticking the relevant checkbox and entering a value.

Any pulses shorter than the Lower limit will not be recorded, and similarly any pulses longer than the Upper limit will also not be recorded. Limits are in milliseconds.

In cases where interference is causing additional Valid Card register increments to be recorded, simply setting the Lower and Upper values either side of the actual pulse width expected from the card reader itself should fix that issue, but it is recommended that sources of such interference are investigated and corrected, if possible.

Tailgate Alarms Using MQTT

Instead of using a physical relay as the alarm output (or as well as), you could use the Vectors MQTT output functionality. MQTT is a mechanism which pushes out selected data ‘topics’ over an IP connection whenever new data is available. This means that as soon as there is a change, data is received within a few seconds.

As long as the above Tailgate Alarm register is configured correctly it will increment whenever a tailgate event occurs and that is the only change that MQTT needs in order to trigger sending of a data message. It should be noted that increments on the ‘Line’ and ‘Valid Card’ registers will also result in an MQTT message being sent, but by comparing the latest values received with the preceding ones, a Tailgate event can easily be identified in software. This makes remote monitoring of Tailgate alarms possible.

The setup of MQTT involves connection to an MQTT broker and other relevant settings and is therefore outside of the scope of this document. For more details about MQTT, see additional configuration documents available from the Irisys partner portal.

TESTING

There are a number of tests that should be performed in order to ensure correct operation.

1. Check that the swipe card reader interfacing is correct. When you swipe your access card, the corresponding ('Valid Card') register should increment by one. If it doesn't, check:

• Wiring/connections from access control system to USB-IO module.
• Relay input setup on the Vectors Relay tab.
• Interfacing - is the access controller wired/programmed to output a valid card signal for each swipe card?

2. Check that people are being counted correctly as they walk in through the secure door. When a person walks in the corresponding ('Line 1") register should increment by one. Importantly, this register should increment for every person who enters, regardless of whether they swiped a valid card or not. If it doesn't, check:

• That the line is positioned around the door.
• The line isn't too close to the door.
• It is not possible to walk in without crossing the line.
• The direction of the line is pointing into the secure area.
• There are no options set on the line which prevent a person being counted - height filters, staff detection.

3. The tailgate alarm works correctly. When a tailgate alarm occurs the corresponding ("Tailgate Alarm") register should increment. To test this walk through without swiping your card - this should result in:

The Line 1 register should increment by one, and immediately the Tailgate Alarm register should also increment by one. Importantly the the Valid Card register should be unchanged. If that doesn't happen, check:

• The setup of the tailgate alarm register. Ensure that the Line 1 and Valid Card registers are correctly assigned.

4. The tailgate alarm output from the Vector is received correctly at the access controller. Every time the tailgate alarm register increments there should be a corresponding pulse received at the access control system. This is then used to drive other events. If that signal is not received, check:

• Wiring/connections from USB-IO to access control system.
• Relay outputs settings on the Vectors Relay tab.
• Interfacing - is the access controller wired/programmed to accept a pulse input from the Vectors IO module output?

People Counting

As well as tailgate detection, a Vector's main function is as a regular automatic people counter, and it can do this at the same time as tailgate detection, if required. In this way tailgate detection and people counting will operate independently and concurrently on the same device.

Although a single counting line can be used for more than one function – i.e. for use for tailgate detection and people counting – because of the different preferred count mode for counting it is better to add separate lines for counting only.

To do this, click the ‘Add Register’ button…
…and choose the ‘Line’ type register, and click ‘Next’:
Give the Line register a relevant name, and click ‘Next’:
Leave the Count Mode as the default ‘Deferred no u-turns’. Click ‘Next’:
Click the ‘Add Register’ button to finish:

You’ll now see the new IN and OUT count line registers in the list, and the corresponding lines on the ground plane view. The last thing to do is position those lines for people counting.

In most cases the new IN and OUT counting lines can be positioned in exactly the same position as the existing Line used in the Tailgate functionality. Just remember that the ‘OUT’ line will need to be pointing in the opposite direction.

Here we can see the two new lines with the (Blue) ‘OUT’ line on top of the (white) ‘IN’ line, and existing green ‘Line 1’, which is now completely covered: