configuring GS1-21P0 to p3-550 configuring GS1-21P0 to p3-550 Nandit (Computer) (OP) 28 Dec 13 22:26 Hi , I am trying to operate GS1-21P0 using RS-485 serial port in P3-550. I am using modbus RTU protocal to communicate. However, my GS1-21P0 is showing an error code cE01. Can any one help on this. RE: configuring GS1-21P0 to p3-550 danw2 (Industrial) 25 Jan 14 09:56 All those model numbers are just Greek to me. What are they, functionally? What's the error code mean? RE: configuring GS1-21P0 to p3-550 xnuke (Electrical) 26 Jan 14 11:51 To clear up any confusion, they are a VFD and PAC from AutomationDirect, respectively. RTFM. It says: Quote (GS1 Manual)Communications Warning: Illegal command code - The command code received in the command message is not available for the AC drive. In other words, you're sending a command from the PAC that the drive does not recognize. Rewrite the command you're sending so it is valid for the drive. xnuke "Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged. Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.