NDC BETA LaserMike LaserSpeed Pro 8500-4, Instruction Handbook Manual

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10-6 LaserSpeed Pro 8500-4 Instruction Handbook:
PROFINET I/O™
9 Read String Segment
10 Write String Segment
11 Save String setting
12 Measurement Table Enumerate
13 Read Long (4-byte) measurement value
14 Read Float (4-byte Real) measurement value
10.3.3 PKW Idle Command (Command Code 0)
The gauge responds with all
zeroes in the response data and a “success” response code. It is recommended
that the idle command be issued before starting Profinet IO communication, and during operation if no data-
base items need to be read or written.
10.3.4 PKW Enumeration Command (Command Code 1)
This command allows the LaserSpeed Pro database to be enumerated. A single database item can be enu-
merated with each command/response exchange; this makes it quite slow to enumerate the entire database.
There is no requirement to enumerate the database. The database section of this document provides details
of database item identifiers, types, and access permissions, and it is possible to use this published infor-
mation directly with the other database services. The enumeration service allows generic test programs to be
written that have no prior knowledge of the LaserSpeed Pro database.
The Profinet IO master provides an incrementing enumeration index within the command qualifier field. Usu-
ally this would begin with an enumeration index of 0, and increment after each successful enumeration ex-
change. Enumeration is complete when the response code is set to “unknown item.”
For a successful enumeration, the gauge sets the PKW response data as follows:
Bit: 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Word
2:
Database Item Identifier
Word
3:
Database Item Access Flags Database Item Type
Database Item Identifier: identifier to be used with other database services
Database Item Type: 0=long, 1=float, 2=string, 255=unknown
Database Item Access Flags: 0x01=non volatile, 0x02=read-only, 0x04=constant (not changed by gauge)