Veichi AC310 Service Manual page 44

⚫ Communication master (parameter Fd.00 is 1, Fd.09 is 0022), slave (parameter Fd.00 bit 0,
F0.02 is 2, F0.03 is 6), change the frequency of the master, the frequency on the slave is
synchronised with the master signal
⚫ Swap the master and slave parameters and repeat the above operation
RS485 communication failure is usually due to the damage of 485 communication IC
U1, common mode inductor L1, TSS tube D4/D5, test and replace the bad devices, external
keypad RS485 communication test method is consistent with the above.
4. Repair Tips
⚫ When communicating with multiple AC drives or over long distances, care should be taken
to detect whether 120Ω terminal resistances have an effect on communication (i.e., whether
removing 120Ω and the presence of 120 ohms has an effect on communication). As shown in
the figure（R=120Ω）
Debugging
software
⚫ Shielded cable single PE or double PE (as shown in SHIELD)
Two operating grounds, GNG, are connected (PIN8 pin, as shown
⚫
⚫ Serial 485 signal isolator
5. Device bit number and specification
485 Communication IC
R
RS485ap RS485ap RS485ap
pliances pliances pliances
U1=SP485EEN-L
AC310 Universal AC Drive Service Manual
R
RS485ap
pliances
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