ILX69-PBM ♦ CompactLogix™ or MicroLogix™ Platform
Communication
PROFIBUS Master Communication Module
User Manual
ProSoft Technology, Inc.
Page 75 of 113
Slave Diagnostics Request Registers
Bytes 4 to 7 contain the
Slave Diagnostics Request Register.
In combination with the
handshake request bits, these registers are used to provide an easy method to execute
a diagnostics request to a specified PROFIBUS slave.
The Slave Diagnostics Command can be executed by using the corresponding
handshake request bit HsReq0 in the Device Command Register (see section Device
Command Registers (page 73)). The result of the Slave Diagnostics Command can be
read in the Slave Diagnostics field of the input array.
Byte
Offset
Data
Type
Structure
Member
Description
4
SINT
SLA
Slave Address
5
SINT
FNC
Function value
6
SINT
Reserved
Reserved
7
SINT
Reserved
Reserved
Slave Address
Address of the slave of which the diagnostics data are requested.
Function
If FNC is 0, the diagnostics data is requested from the internal buffer of the ILX69-PBM.
This is the recommended method since the ILX69-PBM always has the most recent
slave diagnostics data in its internal buffer.
If FNC is 1, the diagnostics data is requested directly from the slave itself. This is not the
preferred method because it causes additional bus loading and will influence the bus
cycle time.
Note:
The same Slave Diagnostics function can also be executed by CIP
message functionality described later in this manual. The slave diagnostics
can only give the mandatory diagnostics information of a slave. Extended
diagnostics information can be received with the CIP message
functionality.
