The frequency communication of Jintian inverter can only be written but not read.

The reasons why the frequency communication of Jintian inverter can only be written but not read may be as follows:

1. Communication protocol setting problem: The communication protocol of Jintian frequency converter may only be set with the writing function, but not with the reading function, which makes it impossible to read the frequency information.

2. Communication interface problem: The communication interface of Jintian inverter may only support the writing function, but not the reading function, which makes it impossible to read the frequency information.

3. Communication parameter setting: During communication, some parameters may need to be set before reading operation. If these parameters are set incorrectly, the frequency information cannot be read.