Mitsubishi Heavy Industries MHI FDU71VNXVF1 Technical Manual page 258

(20) External input/output control (CnT or CnTA)
Be sure to connect the wired remote control to the indoor unit. Without wired remote control remote operation by CnT is not
possible to perform.
・ CnT
Option
1
2
XR1
CnT 3
XR2
Blue
4
12V XR3
5
XR4
6
XR5
■ Priority order for combinations of CnT and CnTA input.
① Operation stop level
② Operation stop pulse
③ Operation permission/prohibition level CnT ③ > CnTA ① CnT ③ > CnTA ② CnT ③ + CnTA ③
CnT
④ Operation permission/prohibition pulse CnT ④
⑤ Cooling/heating selection level CnT ⑤ / CnTA ①
⑥ Cooling/heating selection pulse CnT ⑥ / CnTA ①
Note (1) Following operation commands are accepted when the operation prohibition is set with CnTA as indicated with *.
Individual operation command from remote control, test run command from outdoor unit and operation command from optional device, CNT input.
Reference: Explanation on the codes and the combinations of codes in the table above
1.  In case of CnT "Number", the CnT "Number" is adopted and CnTA is invalidated.
2.  In case of CnTA "Number", the CnTA "Number" is adopted and CnT is invalidated.
3.  In case of CnT "Number"/CnTA "Number", the CnT "Number" and the CnTA "Number" become independent functions each other.
4.  In case of CnT "Number" + CnTA "Number", the CnT "Number" and the CnTA "Number" become competing functions each other.
5.  In case of CnT "Number" > CnTA "Number", the function of CnT "Number" supersedes that of CnTA "Number".
6.  In case of CnT "Number" < CnTA "Number", the function of CnTA "Number" supersedes that of CnT "Number".
(The "Number" above means ① - ⑥ in the table.)
(a) Output for external control (remote display)
Following output connectors (CnT) are provided on the indoor control PCB for monitoring operation status.
① Operation output: Outputs DC12V signal for driving relay during operation
② Heating output: Outputs DC12V signal for driving relay during heating operation
③ Thermostat ON output: Outputs DC12V signal for driving relay when compressor is operating.
④ Error output: Outputs DC12V signal for driving relay when anomalous condition occurs.
(b) Remote operation input
Remote operation input connector (CnT-6 or CnTA) is provided on the indoor control PCB.
However remote operation by CnT-6 or CnTA is not effective, when "Center mode" is selected by center controller.
In case of plural unit (twin, triple, double twin), remote operation input to CnT-6 or CnTA on the slave indoor unit is
invalid.
Only the "LEVEL INPUT" is acceptable for external input, however when the indoor function setting of "Level
input (Factory default)" or "Pulse input" is selected by the function for "External input" of the wired remote control,
operation status will be changed as follows.
(i) In case of "Level input" setting (Factory default)
Input signal to CnT-6 or CnTA is OFF→ON ...... unit ON
Input signal to CnT-6 or CnTA is ON→OFF ...... unit OFF
Operation is not inverted.
CnT-6 or CnTA input
Note: The latest operation has priority
It is available to operate/stop by remote control or center control
① Operation output
② Heating output
③ Thermostat ON output
④ Error output
⑤ Remote operation input
① Operation stop ② Operation stop
level pulse
CnT ① CnT ①
CnT ② CnT ②
CnT ④
CnT ⑤ / CnTA ②
CnT ⑥ / CnTA ②
OFF
Unit A
OFF
ON
Unit B
OFF
(CnT-2: XR1)
(CnT-3: XR2)
(CnT-4: XR3)
(CnT-5: XR4)
(CnT-6: Volt-free contact)
CnTA
③ Operation ④ Operation
permission/prohibition permission/prohibition pulse
CnT ① + CnTA ② CnT ①
CnT ② + CnTA ③ CnT ②
CnT ③
CnT ④ + CnTA ③※ CnT ④
CnT ⑤ / CnTA ③※ CnT ⑤ / CnTA ④
CnT ⑥ / CnTA ③ CnT ⑥ / CnTA ④
ON
OFF
ON
OFF
ON
OFF
Remote Remote
control OFF control ON
257
- -
ON
'12 • PAC-T-178
・ CnTA
CnTA
Blue
12V
XR6
Note (1)  C nTA function can be
changed by RC-EX1A.
⑤ Cooling/heating ⑥ Cooling/heating
selection level selection pulse
CnT ① / CnTA ⑤ CnT ① / CnTA ⑥
CnT ② / CnTA ⑤ CnT ② / CnTA ⑥
CnT ③ / CnTA ⑤ CnT ③ / CnTA ⑥
CnT ④ / CnTA ⑤ CnT ④ / CnTA ⑥
CnT ⑤ CnT ⑤
CnT ⑥ CnT ⑥
ON
ON
ON