RKI Instruments AirLink 7543 User manual

www.rkiinstruments.com
AirLink 7543 Gas Monitor
Operator’s Manual
Part Number: 71-0537
Revision: P2
Released: 8/2/21

2 • Product Warranty AirLink 7543 Gas Monitor Operator’s Manual
Product Warranty
RKI Instruments, Inc. (Manufacturer) warrants its products to be free of defects in workmanship and
materials—under normal use and service—for one year from the date of purchase from the
manufacturer or from the product's authorized reseller.
The manufacturer is not liable (under this warranty) if its testing and examination disclose that the
alleged defect in the product does not exist or was caused by the purchaser's (or any third party's)
misuse, neglect, or improper installation, testing or calibrations. Any unauthorized attempt to repair or
modify the product, or any other cause of damage beyond the range of the intended use, including
damage by fire, lightning, water damage or other hazard, voids liability of the manufacturer.
Any repaired or replaced product or part has either a 90-day warranty or the remainder of the initial
warranty period (whichever is longer).

AirLink 7543 Gas Monitor Operator’s Manual Product Warranty • 3
Table of Contents
Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
About the AirLink 7543 Gas Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 2: Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Terminal Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Internal Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter 3: Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Mounting the AirLink 7543 Gas Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Wiring the AirLink 7543 Gas Monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Chapter 4: Startup and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Power On/Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Normal Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
LED Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Chapter 5: Setup Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Entering Setup Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Channel Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Relay Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
View System Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Exiting Setup Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Chapter 6: Advanced Configuration Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Entering the Advanced Configuration Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Adjusting the LCD Contrast. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Restore Factory Default Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Relay Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Modbus Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
WireFree Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Exiting the Advanced Configuration Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4 • Product Warranty AirLink 7543 Gas Monitor Operator’s Manual
Chapter 7: Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Calibration Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Relay Test Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Chapter 8: Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Appendix A: Relay Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Appendix B: RS-485 Modbus Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Modbus Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

AirLink 7543 Gas Monitor Operator’s Manual Chapter 1: Introduction • 5
Chapter 1: Introduction
Overview
This chapter briefly describes the AirLink 7543 Gas Monitor. This chapter also describes the AirLink
7543 Gas Monitor Operator’s Manual (this document). Table 1 at the end of this chapter lists the
specifications for the AirLink 7543.
About the AirLink 7543 Gas Monitor
The AirLink 7543 can monitor up to 6 WireFree sensors. All configured channels are displayed every
three seconds (scanned). When one channel indicates a gas reading, the monitor locks to that channel.
If two or more channels are indicating a gas reading, the monitor scans those channels every three
seconds. The user can manually scan channels by pressing ADD to move forward through channels or
SUB to move backward through channels. The currently displayed channel will remain on the display
for one minute and then the instrument will return to normal scanning.
There are three 5 Amp relays with 4 Amp fuses. The third relay may be configured as a Fault relay.
This Fault relay will activate if any Fault is generated by the monitor or if any sensor that the monitor
is configured to monitor goes into Fault. The Fault relay is removed from any further configurable
options in Channel Setup—leaving only two relays for each channel. All relays can be configured to be
either latching or auto resetting. The relays can be configured with different set points for alarm
conditions for each channel, allowing each channel to have their own gas level set points.
An optional strobe and/or horn can be ordered. The strobe is installed on the top of the housing and is
wired into the first relay. The horn is installed on the bottom of the housing and is wired into the
second relay.
All relays have a 10% of value of hysteresis on the set points. This prevents the relays from rapidly
switching on and off if gas readings are jumpy. Once the threshold value of a relay is reached, the relay
is activated. However, the AirLink 7543 screen will not lock on the channel with a triggered relay
while the reading is below the Relay Set Point (the user must scroll through the channels to find the
channel with a triggered relay). When the gas reading decreases below the threshold value, the relay
must be 90% of the initial threshold value to deactivate.

6 • Chapter 1: Introduction AirLink 7543 Gas Monitor Operator’s Manual
About this Manual
The AirLink 7543 Gas Monitor Operator’s Manual uses the following conventions for notes, cautions,
and warnings:
NOTE: Describes additional or critical information.
CAUTION: Describes potential damage to equipment.
WARNING: Describes potential danger that can result in injury or death.
Caution: refer to accompanying documentation
~ Vac (AC voltage)
Vdc (DC voltage)
!

AirLink 7543 Gas Monitor Operator’s Manual Chapter 1: Introduction • 7
Specifications
Table 1 lists specifications for the AirLink 7543.
Table 1: AirLink 7543 Specifications
Description Specification
Input Power 110/240 VAC
or
12 - 35 VDC
Current Draw 275 mA max
Operating Temperature -40°F to 158°F (-40°C to 70°C)
Input Signal • Up to 6 WireFree sensor assemblies
Output • RS-485 Modbus
OR
• WirelessHART
Construction (housing) Fiberglass with clear window (NEMA 4)
Dimensions 20.8 in. H x 10.1 in. W x 4.6 in. D
(52.8 cm H x 25.7 cm W x 11.7 cm D)
Weight 12.8 lbs.
Mounting 4 mounting feet (6” W x 10.2” T); 1/4” diameter max
mounting bolt/screw size
User Controls Program buttons: MENU, ADD, SUB
Display Graphical LCD (128x64), transflective, sunlight
readable, LED backlight
Relays • 3 relays with 4A fuses
• SPDT, Form C (common, normally open, and
normally closed contacts)
Radio Options • 2.4 GHz, ISM, 125 mW
OR
• 900 MHz, 200 mW
Standard Accessory • Operator’s manual (this document)
• Magnetic wand
Optional Accessories •Strobe
•Horn

8 • Chapter 2: Description AirLink 7543 Gas Monitor Operator’s Manual
Chapter 2: Description
Front Panel
Figure 1: Front Panel

AirLink 7543 Gas Monitor Operator’s Manual Chapter 2: Description • 9
Terminal Board
Figure 2: Terminal Board

10 • Chapter 2: Description AirLink 7543 Gas Monitor Operator’s Manual
Internal Components
Figure 3: Internal Components
Note: Delta power supply only included
with AC-powered version.

AirLink 7543 Gas Monitor Operator’s Manual Chapter 3: Installation • 11
Chapter 3: Installation
Mounting the AirLink 7543 Gas Monitor
1. Select the mounting site. When you select the mounting site, consider the following factors:
• Is an AC or DC power source available?
• Is a vertical surface available to mount the AirLink 7543?
• Is there enough room to open the housing door and make wiring connections?
• Are the display screen and status lights visible?
2. Close and latch the housing door.
3. Prepare the selected mounting site as required to mount the AirLink 7543. It should be mounted at
eye level (4 1/2 to 5 feet from the floor). Refer to Figure 4 for the outline and mounting
dimensions.
4. Position the monitor on the vertical mounting surface.
5. Insert 1/4” bolts or screws through the slots in the mounting feet at each corner of the housing to
secure the housing to the mounting surface.

12 • Chapter 3: Installation AirLink 7543 Gas Monitor Operator’s Manual
Figure 4: Outline and Mounting Dimensions
6.0
10.1
4.6
10.2
20.8
900 MHz Version
18.9
Ø .3 x .2
2.4 MHz Version
16.6
18.5

AirLink 7543 Gas Monitor Operator’s Manual Chapter 3: Installation • 13
Wiring the AirLink 7543 Gas Monitor
This section describes procedures for DC power source wiring, AC power source wiring, Modbus out
wiring, fault indicator wiring, and relay wiring.
The following wiring connections must be made before starting up the AirLink 7543.
RKI recommends using a minimum of 22 AWG wire. Different loads require different gauge wire. Use
an appropriate wire size, depending on the voltage and current requirements.
CAUTION: The internal components can be static sensitive. Use caution when opening the enclosure
and handling internal components.
WARNING: Make all connections to the AirLink 7543 before you plug in or turn on the AC or DC
power source. Before you make any wiring adjustments, always verify that all power
sources are not live.
Connecting a DC Power Source
NOTE: The AirLink 7543 is configured for AC or DC operation, depending on how it is ordered. If
you are using AC power as the primary power source, go to the next section, “Connecting an
AC Power Source”.
Provide a clean and stable 12-35 VDC. Failure to do so may cause the unit (and any wired sensors that
are connected to the unit) to not operate properly.
Voltage spikes higher than 35 VDC may damage the unit.
1. Open the enclosure box to expose the Front Panel.
2. Unscrew the two thumb screws on the Front Panel.
3. Open the Front Panel so that the Terminal Board is exposed.
4. Locate the Power Terminal (on the left side of the Terminal Board) and connect the DC-live wire
(red) to the terminal marked “+V”.
5. Connect the DC-ground wire (black) to the terminal marked “GND”.

14 • Chapter 3: Installation AirLink 7543 Gas Monitor Operator’s Manual
Figure 5: DC Wiring
6. Close the Front Panel.
7. Screw in the thumb-screws.
8. Close the enclosure box.
9. Clamp down the enclosure latches.
Connecting an AC Power Source
NOTE: The AirLink 7543 is configured for AC or DC operation, depending on how it is ordered. If
you are using DC power as the primary power source, go to the previous section, “Connecting
a DC Power Source”.
WARNING: Verify that the power source is unplugged or turned off before you continue with this
procedure.
1. Open the enclosure box to expose the Front Panel.
2. Unscrew the two thumb-screws on the Front Panel.
3. Open the Front Panel so that the AC (Delta) Power Supply is exposed.

AirLink 7543 Gas Monitor Operator’s Manual Chapter 3: Installation • 15
4. The power supply is factory wired to the Terminal Board.
5. For versions that came with a pre-wired AC line cord: there are three wires (black, white and
green) pre-wired from the Delta power supply terminals “L” (AC Load IN), “N” (AC Neutral IN),
and “EG” (Chassis GND or Earth GND). This set of wires will be used to plug into an AC power
outlet ONCE ALL WIRING CONFIGURATIONS ARE COMPLETE.

16 • Chapter 3: Installation AirLink 7543 Gas Monitor Operator’s Manual
6. For versions that did not come with a pre-wired AC line cord:
• Connect a line wire from the AC power source to the power supply’s “L” terminal.
• Connect a neutral wire from the AC power source to the power supply’s “N” terminal.
• Connect a ground wire from the AC power source to the power supply’s “EG” terminal.
NOTE: If the AirLink 7543 was not ordered with any housing holes, at least one hole will have to be
drilled to bring in AC power.
Figure 6: AC Wiring
7. Close the Front Panel.
8. Screw in the thumb-screws.
9. Close the enclosure box.
10. Clamp down the enclosure latches.

AirLink 7543 Gas Monitor Operator’s Manual Chapter 3: Installation • 17
RS-485 Modbus Wiring (Modbus Out)
NOTE: The Modbus output is not available if Wireless HART is being used.
1. Open the enclosure box to expose the Front Panel.
2. Unscrew the two thumb-screws on the Front Panel.
3. Open the Front Panel so that the Terminal Board is exposed.
4. Locate the Modbus Out Terminal Block.
5. Connect the yellow wire from a DB-9 connector (or the connector-type that best suits your
application) to the terminal labeled “A” on the Modbus Out Terminal Block.
6. Connect the white wire from a DB-9 connector to the terminal labeled “GND” on the Modbus Out
Terminal Block.
7. Connect the brown wire from a DB-9 connector to the terminal labeled “B” on the Modbus Out
Terminal Block.
8. Plug the DB-9 connector into a PLC.
Figure 7: Modbus Out Wiring
9. Close the Front Panel.
10. Screw in the thumb-screws.
11. Close the enclosure box.
12. Clamp down the enclosure latches.

18 • Chapter 3: Installation AirLink 7543 Gas Monitor Operator’s Manual
WirelessHART Setup
If the AirLink 7543 was ordered with WirelessHART, a module will be installed on the Terminal
Board and the Modbus output will not be user-accessible.
1. Drill a hole in the housing and install the 2.4 GHz WirelessHART antenna. If the antenna receiving
the detector signal is also a 2.4 GHz antenna, then remote either the receiving antenna or the
WirelessHART antenna away from the AirLink 7543. If the receiving antenna is a 900 MHz
antenna, then the WirelessHART antenna can be installed on the AirLink 7543’s enclosure.
WARNING: Seal the hole for the antenna or for the antenna cable to ensure water does not enter
the enclosure.
2. Connect a HART communicator to the “H+” and “H-” terminals on the Terminal Board to make
configuration settings.

AirLink 7543 Gas Monitor Operator’s Manual Chapter 3: Installation • 19
Fault Indicator Connection
The Fault terminal provides an output to power some form of Fault indicator. The Fault terminal is wet
contact, uses the same supply voltage that powers the board, provides 500 mA maximum, and is a DC
only output.
The fault terminal’s failsafe operation can be configured as described in step 5 on page 29.
1. Open the enclosure box to expose the Front Panel.
2. Unscrew the two thumb-screws on the Front Panel.
3. Open the Front Panel so that the Terminal Board is exposed.
4. Locate the Fault Terminal Block on the terminal board.
5. Connect a positive (red) wire to the terminal labeled “+”.
6. Connect a negative (black) wire to the terminal labeled “-”.
Figure 8: Fault Indicator Wiring

20 • Chapter 3: Installation AirLink 7543 Gas Monitor Operator’s Manual
Relay Wiring
The AirLink 7543 has four relays. Two relays are intended for gas alarms, one relay can be used for
gas alarms or a fault condition, and one relay is a dedicated fault relay. Each of the four relays may be
setup as Normally Open (NO) or Normally Closed (NC). See page 35 for more explanation about relay
actuation.
NOTE: If installed, the strobe is factory wired to the Relay 1 terminals and the horn is factory wired
to the Relay 2 terminals.
1. Open the enclosure box to expose the Front Panel.
2. Unscrew the two thumb-screws on the Front Panel.
3. Open the Front Panel so that the Terminal Board is exposed.
4. Locate the Relay Terminal Blocks on the Terminal Board.
5. Connect the alarm device’s “+ (H)” terminal to the NO or NC terminal on the relay terminal block.
NOTE: It is recommended that the relay connections are wired as normally-open (NO). However,
normally-closed (NC) wiring configurations provide an inherent fail-safe and may be
preferred.
6. Connect the alarm device’s “- (N)” terminal to an external power source’s “- (N)” terminal.
7. Connect the external power source’s “+ (H)” terminal to the COM terminal on the relay terminal
block.
Figure 9: Relay Wiring