Pilz PSS SB HYD, Basic license - Manual (Page 192)

6-130 Modular Block System: Hydraulic Presses
Standard Function Blocks
• Y: Output parameters for operating a valve
Y = 0:
Valve off
Y = 1: Valve on
• ERR: This output parameter is set as soon as a fault is discovered.
ERR = 0:
No fault found
ERR = 1: Fault found
Function
• Switches on the valve in its start position only (input parameter S = 1,
valve de-energised, acknowledgement from valve is present).
• Monitors position through acknowledgement of the valve's position (input
parameter S) within a maximum reaction time. The reaction time for
switch on and switch off may be selected individually:
- Reaction time when switching on the valve:
When switched on, the valve must leave its start position within a
maximum time (reaction time). The maximum reaction time when
switching on the valve can be set via the input parameter
TOn. If the
maximum reaction time is exceeded, an error message will be issued
(output parameter
ENBL = 0 and ERR = 1) and the valve will switch off
immediately (output parameter Y = 0). A reset will be necessary (see
also under “Error messages”).
- Reaction time when switching off the valve:
When switched off, the valve must reach its start position within a
maximum time (reaction time). The maximum reaction time when
switching off the valve can be set via the input parameter
TOff. If the
maximum reaction time is exceeded, an error message will be issued
(output parameter
ENBL = 0 and ERR = 1) and a reset will be
necessary (see also under “Error messages”).
• Monitors position through acknowledgement of the valve's position (input
parameter S), without setting a maximum reaction time (input parameter
TOn = 0 and TOff = 0).
When monitoring the position of a valve without monitoring the reaction
time, SB087 checks that it leaves its start position (valve de-energised,
acknowledgement present) at least once in each working cycle (valve
switching on and off). If this is not the case, SB087 will register an error
(output parameter
ENBL = 0 and ERR = 1) and the valve will switch off
immediately (output parameter Y = 0). A reset will be necessary (see
also under “Error messages”).
SB087