Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE - Manual (Page 174)

7-50 OPERATOR INTERFACE TERMINAL PV-550 REV E
1557-UM050F-EN-P – June 2013
Advanced Screen Operations
A number of advanced functions have been incorporated into the terminal. These operations are not
required to operate the drive. They are meant as service tools for trained technicians and have been
included here only for completeness.
All operations are accessed via a two key sequence.
Communications Statistics
The screen, depicted in Figure 82 shows statistics involving the serial communications between
the terminal and the drive as well as the contents of the transmit and receive buffers. It is called
from any screen (except the PRINTER screen), by pressing the [F10] key and the [cursor down]
key at the same time.
The ERRORS show the number of occurrences of a particular error since the last time the
counters were reset.

Parity: number of parity errors in characters received.

Framing: number of framing errors in the characters received.

Overrun: number of characters received which were not read prior to accepting the next
character.

Resends: number of times the terminal had to resend data due to a NACK being sent by
the drive.

Timeouts: number of times the terminal did not receive data from the drive within a
specified time period.

Chksum: number of times the terminal detected a checksum error in the data it received
from the drive.

Discard: number of characters discarded by the terminal as they were not what was
anticipated.

Control: number of control codes which did not conform to the anticipated ACK or NACK.
The terminal will have assumed ACK, which if wrong will result in a time-out error.

Seqnce: number of responses from the drive which did not correspond to the last request
sent.
Figure 82 – Communications Statistics & Buffer