38
Curtis 1212S Manual,
Rev. B
APPENDIX B
EN 13849 COMPLIANCE, CURTIS 1212S CONTROLLER
Since January 1, 2012, conformance to the European Machinery Directive
has required that the Safety Related Parts of the Control System (SRPCS)
be designed and verified upon the general principles outlined in EN13849.
EN13849 supersedes the EN954 standard and expands upon it by requiring
the determination of the safety Performance Level (PL) as a function of Desig-
nated Architecture plus Mean Time To Dangerous Failure (MTTFd), Common
Cause Faults (CCF), and Diagnostic Coverage (DC). These figures are used by
the OEM to calculate the overall PL for each of the safety functions of their
vehicle or machine.
The OEM must determine the hazards that are applicable to their vehicle
design, operation, and environment. Standards such as EN13849-1 provide
guidelines that must be followed in order to achieve compliance. Some indus-
tries have developed further standards (called type-C standards) that refer to
EN13849 and specifically outline the path to regulatory compliance. EN1175-1
is a type-C standard for battery-powered industrial trucks. Following a type-C
standard provides a presumption of conformity to the Machinery Directive.
Curtis 1212S controllers comply with these directives using basic “watch-
dog” test circuits; see the simplified block diagram in Figure B-1.
Fig. B-1
Safety channel
block diagram, Curtis
1212S controller.
To mitigate the hazards typically found in machine operations, EN13849
requires that safety functions be defined; these must include all the input, logic,
outputs, and power circuits that are involved in any potentially hazardous op-
eration. Three safety functions are defined for the Curtis 1212S controller: (1)
crushing due to unintended or uncontrolled movement; (2) crushing through
loss of STO/braking; and (3) loss of stability from excessive speeds, as specified
by vehicle limits.
Dashed lines = monitor and test connections
1. Throttle Wiper
2. Mode
3. Emergency Reverse
4. Interlock
5. Forward Switch
6. Reverse Switch
7. Keyswitch
INPUT
1. MCU
2. Logic Supply
LOGIC
1. Powerbase
2. Brake Output
3. Main Relay Driver
OUTPUT
TEST EQUIPMENT
1. Watchdog
2. Powerbase Fault
3. Driver Sense
4. Pot High/Low
5. HPD and SRO
6. Range Checks
APPENDIX B: EN 13849 COMPLIANCE
