SFA-5000 • SFA-10000 Profibus
6.8 Set_Slave_Address command (SAP55 service)
WARNING
SAP55 service can only be accomplished by a
Class 2 DP Master (DPM2)
. Class
1 Masters (DPM1) cannot accomplish the SAP55 service.
Lika SFA draw-wire encoders are designed to allow the Slave address setting
either via hardware switches (see the “4.7 Node Address: DIP A (Figure 3 and
Figure 4)” section on page 30) or via a bus command by means of the SAP55
service.
The Service Access Point SAP55 Set_Slave_Address allows to change the address
stored in the internal memory of a Slave device. SAP55 service is part of the
Profibus specifications and allows to change the internal memory address in the
event that the device does not provide switches for setting its address or they
are not usable. The address stored in the internal memory of the Slave is used
only if the hardware switches are set to “126”. The address stored at factory by
Lika Electronic is “125”. On the contrary, if the hardware switches are set to any
value between 0 and 125, then the external switches will determine the Slave
address.
WARNING
Please note that the node address set via hardware switches and the node
address stored in the internal memory are independent from each other! The
node address stored in the internal memory can be changed only by means of
the SAP55 service and the Set_Slave_Address command.
MAN SFA_5000_10000_PB E 1.0
Profibus® interface
64 of 72
At power-up the system checks
the node address setting
in the dip-switches.
If the dip-switches value is 126,
then the system uses the address
stored in the internal memory
(factory value: 125)
Via SAP55 it is possible to change
the Slave address currently
stored in the internal memory.
If the dip-switches value is
between 0 and 125, then the system
uses the dip-switches address
(factory value: 1)
