Error 1 on GR2030T-LA1 or GR2030-LA1 means: 
The motor speed exceeds the set value (refer to the maximum speed limits of PA54, PA172).



There could be 4 different causes:

Cause 1- The encoder feedback signal is abnormal
Solution: Check the connection of the motor encoder and its signal cable, or the PA1 settings.

Cause 2- The motor runs due to external forces, with a large acceleration.
Solution: Check mechanical failure and eliminate the effects of external forces.

Cause 3- The set value of PA54 or PA172 (maximum speed limit) is too small.
Solution: Set PA54 and PA172 correctly according to the motor nameplate.

Cause 4- The electronic gear ratio of the position command is too large.
Solution: Set the electronic gear ratio correctly.