Get response of 10 15 from SLC500 using DF1 protocol

Currently I test the communication with AB SLC500/04 using DF1 protocol.I find that the communication is ok when CPU is in program mode .while I set the J4 of CPU module to protect mode,I get two bytes of 0x10 0x15 from PLC.
DO you encounter the same problem? Please tell me if you know how to solve the problem.Thanks.

Chen,

No I have never encountered the same problem because I have never had a need to test the communication with that method.

Why is that a problem? Why do you need to set to "protect mode"?

Has something gone wrong during the firmware upgrade of the CPU ?

Jumper J4 protects the controller operating system, not the user program. From page 159 of the SLC-500 User Manual (Publication 1747-UM011):

Jumper J4, on the bottom corner of the motherboard, provides
write-protection from any download of a new operating
system. The out of the box position of this jumper is PROTECT,
or write-protect. Without the jumper, the processors are
write-protected. Do not place the jumper to the program
position during normal processor use.

Click to expand...

The response 0x10 0x15 is a "NAK", indicating that the controller is rejecting your communication command.

Isn't code ten and illegal command, for example you are asking for a memory device that doesn't actually exist in the PLC.

thanks for your quick replies .
In fact,I found the communication problem from our customer who use a processor of SLC500 5/03.As what Ken Roach said,processor always rejected my command(DF1 full duplex protocol)when Jumper J4 was in protect position(customer's original position).DF1 OPC driver of Kepware got the same response(0x10 0x15).At the same time,RSLinx of AB can get SLC500 5/03 information with driver of DF1.So I tried to change J4 to program position,communication worked well.
Today I test communication with another processor(SLC500 5/04)in the two positions (program and protect).It works well anyway.
TO Izabela: the command format is right,because the same command got right response when J4 in program mode.
To now,I have no way to solve the problem.

Hexadecimal 0x10 is the "Escape" byte that is used to indicate the presence of a transmission control character in DF1.

0x10 0x02 is "start of transmission", 0x10 0x03 is "end of transmission", and 0x10 0x15 is "Negative Acknowledge", or "NAK".

I can't explain why this specific SLC-5/03 is sending "NAK" replies while J4 is in Protect mode and not in Program mode.

My best guess is that a firmware upgrade has been attempted and is incomplete. There is no other reason to move the J4 jumper. The J4 jumper should be in the Protect position except when performing a firmware upgrade.