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• If the request was a read, and the read was performed successfully,
this will be indicated to the master by Resp1:Resp0 changing from 0:0
to 0:1. The parameter number response will equal the accessed
parameter number, and the resulting data read will be placed in the
data / error code response word.
• If the request was a write, and the write was performed successfully,
this will be indicated to the master by Resp1:Resp0 changing from 0:0
to 1:0. The parameter number response will equal the accessed
parameter number, and the data written to the drive will be reflected in
the data / error code response word.
• If an error occurred during the read or write request, this will be
indicated to the master by Resp1:Resp0 changing from 0:0 to 1:1.
The parameter number response will equal the parameter number
that the master was attempting to access, and an error code reflecting
the failure cause will be placed in the data / error code response
word. For a list of possible error codes, refer to section 10.4.
6. In order to perform another parameter read or write, the master must once
again send a “no action” code (Req1=0 and Req0=0), and the PBDP-110
must once again respond with an idle state acknowledge (Resp1=0 and
Resp0=0) before the next read or write action can take place. Until a “no
action” code is sent to the PBDP-110, the interface will ignore all data in
the action bits, parameter number and parameter write data words. Also,
as long as the master sends the “no action” code, the PBDP-110 will loop-
back in the parameter number response word and parameter data / error
code response word whatever data is sent to it in the corresponding
output words.
The above procedure explanation holds true for both drives A and B, using the
respective request and response locations in the output and input data
structures.
10.4 Register Access Error Codes
When a parameter read or write error occurs, one of the following error codes
will be returned in the parameter data response word:
Error Code
Meaning
0x0000......................cannot execute
0x0001......................data error (written data value outside of valid range)
0x0002......................invalid parameter number
0x0064......................attempt to write to a read-only parameter
0x0065......................attempt to read from a write-only parameter
0x0066......................other / unclassified error
