User manual
IEC61131 User and Reference Manual
April 22, 2008
595
Module
Start
Register
End
Register
DF1 Address
Range
SCADAPack AOUT module
40001
40002
11249 to 111250
Slave Mode
The TeleBUS DF1 protocols operate in slave and master modes simultaneously. In slave
mode the controller responds to commands sent by another device. Commands may be sent
to a specific device or broadcast to all devices.
The TeleBUS DF1 protocols emulate the protocol functions required for communication with
a host device which uses the Non-Privileged commands from the DF1 Basic Command Set.
These functions are described below.
Consult the DF1 I/O driver documentation included with the SCADA package, or specific
DF1 documentation, for details on these commands. In most cases a knowledge of the
actual commands is not required to set up the host system.
Broadcast Messages
A broadcast message is sent to all devices on a network. Each device executes the
command. No device responds to a broadcast command. The device sending the command
must query each device to determine if the command was received and processed.
Broadcast messages are supported for function codes that write information.
A broadcast message is sent to station number 255.
Function Codes
The table summarizes the implemented function codes. Note that slave commands at the
protocol layer access the I/O database in physical byte addresses. However, in master mode
the interface to the TeleBUS DF1 protocol accesses the I/O database in physical 16-bit word
addresses. The interface function block MSTR and C function master_message are
described in the Master Mode section below.
The maximum number of 16-bit words that can be read or written with one slave command
message is shown in the maximum column.
F
u
n
ct
io
n
Name
Description
Maximum
00
Protected
Write
Writes words of data to limited
areas of the database.
121
01
Unprotected
Read
Reads words of data from any
area of the database.
122
02
Protected Bit
Write
Sets or resets individual bits
within limited areas of the
database.
30
05
Unprotected Bit
Write
Sets or resets individual bits in
any area of the database.
30
08
Unprotected
Write
Writes words of data to any area
of the database.
121