Quality settings

00C0

Data quality good

Data communications is good and data is good.

The register is read or written to without any problems converting the data.

0055

Clamp low

Data communications is good but the data is uncertain.

The data is clamped at a low limit.

The register is correctly read or written to, but it is necessary to clamp its value to a limit.

The value is smaller than the minimum allowed.

0056

Clamp high

Data communications is good but the data is uncertain.

The data is clamped at a high limit.

The register is correctly read or written to, but it is necessary to clamp its value to a limit.

The value is larger than the maximum allowed.

A string is truncated.

For example, a floating point value is clamped to FLT_MAX.

0040

Quality uncertain/No convert

Data communications is good but the data is uncertain.

The data cannot be converted.

The server may return either a constant in place of the data or return quality information alone.

The data is usable. However, it is not known whether the value is too large or too small.

Incorrect data type.

Floating point is not a number.

For example, 0x000a in a PLC BCD register.

0004

Bad configure/No access

This is a configuration error.

Data communications is good but the data cannot be sent and/or received. The data is bad and cannot be used.

Item cannot be accessed.

The item does not exist or is not available.

The server can communicate with the PLC but cannot access the register.

The server determined the point is not valid.

The PLC responds that the register does not exist, cannot be read, or cannot be written to.

The server cannot access a fenced, write-protected, or read-only item.

The PLC is in a mode that does not permit access to this item.

The number of data bytes is incorrect but the message is otherwise good.

The command or op code is invalid but the message is otherwise good.

The PLC is busy. The server has given up retrying.

0018

No communications

Data communications is down.

Cannot access the PLC due to a communications error.

Data is bad and cannot be used.

The device group is in a slow poll or equivalent mode.

The PLC does not exist and/or is not responding.

There is no link validating the message.

There is a lack of resources in the server. A TSR or driver cannot allocate memory.

There is a lack of resources in the communications link.

The communications link is off-line.

All communications channels are in use.

The network cannot route the message to the PLC.