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65-2658RK-CH4-4 M2A Transmitter Operator’s Manual
jumper installed unless directed to remove it for a Modbus installation. See “Chapter 8: RS-485 Modbus Output”
on page 39 for a description of using the M2A 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 39 for a description of using the M2A 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 4: 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’s programs.
Control Buttons
The M2A includes three push button switches that allow you to enter the M2A’s operating modes, navigate
through the modes, update settings, and save changes to the settings. The push button switches are located along
the bottom edge of the control PCB (see Figure 4). The UP/YES button is on the left, the DOWN/NO button is in
the middle, and the ENTER button is on the right.
ENTER
DOWN/NO
UP/YES
Push Button
Control Switches
Magnetic Switches
ENTER
UP/YES
DOW N/NO
Alarm 1 LED
Alarm 2 LED
Fail LED
RX LED
TX LED
M2A TRANSMITTER
RKI INSTRUMENTS
OLED Display
