4 Safety Function Blocks
4 - 56
NX-series Safety Control Unit Instructions Reference Manual (Z931)
• This FB requires two inputs (
Discrepancy Time
input and
Reset
input) that indicate the guard position
of a safety guard with two switches as defined in ISO 14119 (EN 1088). You can bridge the
S_GuardSwitch1
and
S_GuardSwitch2
inputs when there is only one safety guard switch. The moni-
toring time is the maximum time that is required for both switches to respond when the safety guard
is closed. The
Reset, S_StartReset,
and
S_AutoReset
inputs determine how the FB is reset after the
safety guard is opened.
• The
S_GuardSwitch1
and
S_GuardSwitch2
inputs must both be changed to FALSE to open the
safety guard. The
S_GuardMonitoring
output immediately changes to FALSE when either of the
switches is set to FALSE. The
S_GuardSwitch1
and
S_GuardSwitch2
inputs must both be changed
to TRUE to close the safety guard.
• This FB monitors the symmetry of the switching operation of both switches. The
S_GuardMonitoring
output remains FALSE if only one of the inputs completes the open or close process.
• The operation of the
S_GuardMonitoring
output depends on the time difference between the switch
inputs. If the input values from
S_GuardSwitch1
and
S_GuardSwitch2
are different, monitoring the
discrepancy time is started immediately. If the inputs are still different after the discrepancy time
expires, the
S_GuardMonitoring
output remains FALSE. If both of the corresponding inputs,
S_GuardSwitch1
and
S_GuardSwitch2
, change to TRUE within the time specified by the
Discrepan-
cyTime
input, the
S_GuardMonitoring
output is set to TRUE after the confirmation response.
• Activate the
S_StartReset
and
S_AutoReset
inputs only when you can ensure that no hazardous
state will occur as the result of starting the Safety CPU Unit.
• A FB error will occur if the same variable is assigned to the input and the discrepancy time is set to 0.
• Set
DiscrepancyTime
to a value that is longer than the safety task period.
Refer to the
NX-series Safety Control Unit User’s Manual
(Cat. No. Z930) for application methods for
DiscrepancyTime
.
Function
Содержание NX-SL series
Страница 8: ...CONTENTS 6 NX series Safety Control Unit Instructions Reference Manual Z931 ...
Страница 14: ...Terms and Conditions Agreement 12 NX series Safety Control Unit Instructions Reference Manual Z931 ...
Страница 28: ...Sections in this Manual 26 NX series Safety Control Unit Instructions Reference Manual Z931 ...
Страница 98: ...2 Standard Functions 2 64 NX series Safety Control Unit Instructions Reference Manual Z931 ...
Страница 104: ...2 Standard Functions 2 70 NX series Safety Control Unit Instructions Reference Manual Z931 ...
Страница 110: ...2 Standard Functions 2 76 NX series Safety Control Unit Instructions Reference Manual Z931 ...
Страница 130: ...3 Safety Standard Function Blocks 3 20 NX series Safety Control Unit Instructions Reference Manual Z931 ...
Страница 265: ...I 1 I NX series Safety Control Unit Instructions Reference Manual Z931 Index ...
Страница 268: ...I 4 NX series Safety Control Unit Instructions Reference Manual Z931 Index ...
Страница 269: ......