Nidec Embraco CF01F - Page 33

Figure 22 – Serial control connection
To guarantee serial communication's correct functionality, the signal sent to the Inverter
must be according to the following values (Table 21).
Parameter
Level
TRUE state
-5 V to + 0,7 V
Indefinite state
+ 0,7 V to + 4 V
FALSE state
+ 4 V to + 15 V
Minimum current
2 mA @ + 4 V
Maximum current
15 mA @ + 15 V
Logic Level
Inverted logic
Table 21 – Serial input signal specification
The input resistance (R402) is 1,2 kΩ. The thermostat resistor connected to the Inverter TX
(Pin 1) must be designed considering a maximum current of 1,2 mA through the Inverter
optocoupler.
The circuit in Figure 23 shows the electrical connections to perform serial communication
between an electronic thermostat and CF01F-CF02F Inverter serial connector (CN209).
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