Configuring A Device; Configuring Profibus Pa With An S7-300/ 400 Plc; Cyclic Versus Acyclic Data; Cyclic Data - Siemens SITRANS LR560 Operating Instructions Manual

Configuring a device

Configuring a new device
See

Configuring PROFIBUS PA with an S7-300/ 400 PLC

1) If SITRANS LR560 is not listed in the STEP 7 device catalog, you can download the
GSD file from the Siemens Web site and import it into Step 7. Go to
www.siemens.com/LR560 and click Downloads.
2) Add the SITRANS LR560 "rack": click and drag the SITRANS LR560 folder from the
hardware catalog.
3) Fill the rack with desired modules, by dragging and dropping them from the
hardware catalog.
4) After configuring PROFIBUS PA in steps 2 and 3, download it to the PLC.
5) Add code to the PLC program to read data consistently using the SFC14.

Cyclic versus Acyclic Data

When you request data from a device via PROFIBUS PA, you have two choices. Cyclic
data is provided at every bus scan: acyclic data is requested and provided as needed.
Input information is always requested at every bus scan and is set up as cyclic data.
Configuration information is only needed periodically and is set up as acyclic data.

Cyclic Data

When you configure SITRANS LR560 on the PROFIBUS PA bus, there are two slots
available for modules.
Note:
Each of the slots has to have a module defined in it.
Slot 0 always transmits AIFB1 information
changed to AIFB2 information. If you do not wish to have data transmitted, then you must
use a Free Place module in that slot.
Each of the two Analog Input Function Blocks can be set up to return Level, or Distance.
Within the function blocks, the values are scaled according to the user requirements
AIFB (simulation, mode and status)
(please see
1)
For more information, please see
127.
7ML19985LT01 SITRANS LR560 (PROFIBUS PA) – OPERATING INSTRUCTIONS
on page 40.
1)
; slot 1 defaults to Free Place, but can be
on page 127 for details).
AIFB (simulation, mode and status)
(continued on next page)
on page
Page 131