105BCommunication processor
12.4 Universal serial interface (USS) communication
S7-1200 Programmable controller
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System Manual, 11/2011, A5E02486680-05
Network 1 "PortStatus" port status and
"USS_DRV_DB".USS_Extended_Error
extended error code values are only
valid for one program scan. The
values must be captured for later
processing.
Network 2 The "PortError" contact
triggers the storage of the "PortStatus"
value in "LastPortStatus" and the
"USS_DRV_DB".USS_Extended_Error
value in "LastExtError".
USS drives support read and write access to a drive's internal parameters. This feature
allows remote control and configuration of the drive. Drive parameter access operations can
fail due to errors such as values out of range or illegal requests for a drive's current mode.
The drive generates an error code value that is returned in the "USS_Extended_Error"
variable. This error code value is only valid for the last execution of a USS_RPM or
USS_WPM instruction. The drive error code is put into USS_Extended_Error variable when
the STATUS code value is hexadecimal 818C. The error code value of
"USS_Extended_Error" depends on the drive model. See the drive's manual for a description
of the extended error codes for read and write parameter operations.
12.4.7
General drive setup information
General drive setup requirements
●
The drives must be set to use 4 PKW words.
●
The drives can be configured for 2, 4, 6, or 8 PZD words.
●
The number of PZD word's in the drive must match PZD_LEN input on the USS_DRV
instruction for that drive.
●
The baud rate in all the drives must match the BAUD input on the USS_PORT instruction.
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The drive must be set for remote control.
●
The drive must be set for frequency set-point to USS on COM Link.
●
The drive address must be set to 1 to 16 and match the DRIVE input on the USS_DRV
block for that drive.
●
The drive direction control must be set to use the polarity of the drive set-point.
●
The RS485 network must be terminated properly.