Staubli CS8C, Instruction Manual

Page: 96 / 248

© Stäubli 2009 –
D28070504A
CS8C 96 / 248
5.7.
PROGRAMMABLE LOGIC CONTROLLER (
PLC
OPTION)
The
CS8C
controller can be programmed using
IEC61131-3
standard PLC languages: IL, SFC (GRAFCET), FBD,
LD, ST.
The PLC program must be written on a
PC
in the
PLC
programming environment supplied with
Stäubli Robotics Studio
. It can then be downloaded and executed on the
CS8C
controller.
The
PLC
option requires a
PLC
licence for the
SRS
programming environment, and a runtime licence for each
CS8C
controller.
Without a licence, it is possible to use the
PLC
programming environment for
30
minutes and execute the PLC
program on a
CS8C
for
15
minutes.
5.7.1.
INSTALLATION
SRS
The
PLC
programming environment is supplied with
SRS
. During installation, it is necessary to keep to the
selected
PLC
option.
To activate the
PLC
programming licence, it is necessary to connect the
PLC
key to the
PC
and enter the licence
number using the
SRS
utility (Tools > PLC > Licence).
CS8C
The
PLC
option can be activated on a
CS8C
using the
SRS
options manager (Tools > PLC > Options manager).
After restarting, the option must be shown in the list of software component versions on the
MCP
(Control panel
> Controller > Versions).
5.7.2.
OPERATION IN THE
CS8C
CONTROLLER
PLC
cycle
The
PLC
program in the
CS8C
has access to all the digital and analog inputs and outputs in the system. It can
communicate with a
VAL3
program via the analog or digital outputs of the system.
The
PLC
cycle is carried out as follows:
1.
Reading the inputs and outputs
2.
Execution of a cycle in the
PLC
program
3.
Writing the outputs
4.
Waiting for the rest of the time lapse required to reach the specified cycle time
The cycle time for the
PLC
program is defined in the
PLC
development environment (Generate > Execution
options). It can be modified at any time.
The
CS8C
supports cycle times that are multiples of
4ms
. The sequencing accuracy of the
PLC
cycle (period
between two successive
PLC
cycle starts) is about
± 0.1 ms
.
When the specified cycle time is null, the system automatically adapts the
PLC
cycle time to the system CPU load,
and more specifically to the
VAL3
program. The
PLC
program has then less priority than the
VAL3
program.
Starting
The
PLC
program is physically stored in the controller, in the
/usr/plc
directory. When the controller starts up, the
PLC
program stored in this location is started automatically. The only way of inhibiting the automatic start is to
delete the file from the controller using
Ftp
.
During start-up, if an error is detected in the
PLC
program (
PLC
Input/Output not found in the
CS8C
, or
PLC
output
corresponding to a
CS8C
input), the unit does not start up and the error is displayed in the "Events logger" utility
of the
MCP
.