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Chapter 2: Description
65-2662XL-04 M2A-XL Transmitter
Relay Terminal Strips
The right column of terminal strips consists of, from top to bottom, the fail, alarm 1, and alarm 2
relay terminal strips. They are three-position plug-in style terminal strips. The relay terminal
strips are used to connect devices such as lights and horns that are controlled by the relay contacts.
The relay contacts are rated at 115 VAC, 5 amps. The relay contacts may also be used to control
higher rated relays.
Termination Jumper
A two pin header with a termination jumper installed is located below the Modbus terminal strip.
Leave this jumper installed unless directed to remove it for a Modbus installation. See “Chapter 8:
RS-485 Modbus Output” on page 47 for a description of using the M2A-XL in a Modbus system.
Ground Jumper
A two pin header with a jumper installed is located along the left side of the terminal PCB. Leave
this jumper installed unless directed to remove it for a Modbus installation. See “Chapter 8: RS-
485 Modbus Output” on page 47 for a description of using the M2A-XL in a Modbus system.
Control PCB
The OLED display and control switches are located on the control PCB. It is installed on top of
the terminal PCB by lining up its three spacing standoffs with the banana jacks in the terminal
PCB mounting standoffs and pushing it onto the banana jacks. The jacks retain the control PCB.
Figure 5: Control PCB Component Location
OLED Display
The OLED display is located at the top of the control PCB. It indicates the current gas reading and
displays messages and parameters in the M2A-XL’s programs.
ENTER
UP/YES
DOWN/NO
ENTER
DOWN/NO
UP/YES
Push Button
Control Switches
Fail LED
Magnetic Switches
Alarm 1 LED
OLED Display
RX LED
TX LED
Alarm 2 LED
M2A-XL TRANSMITTER
RKI INSTRUMENTS