Cashco Siemens PS2 I/P - Manual (Page 95)

Operation
95
SIPART PS2 Manual
A5E00074631-01
Explanations of column “Error codes”:
1 Monitoring of control error
In automatic operation the error between setpoint and actual value is
monitored continuously. The fault message is activated with unchanged
control error according to the setting of the parameters 48. TIM, moni-
toring time for setting the fault messages and 49 LIM, response thres-
hold of the fault message. As soon as the control error drops back be-
low the response threshold, the fault message is reset.
2 Monitoring automatic operation
A fault message is generated when the instrument is not in the automa-
tic mode at the appropriate parameter setting “47. FCT”. In this way the
control system can be warned for example when the instrument has
been switched to manual operation or Configuration on site.
3 Digital input DI1 or DI2 active
A fault message is generated when the digital input is activated at the
the corresponding setting of the parameter “47. FCT”, function of the
fault message output and the parameter “42.BIN1”, function digital in-
put 1. This may be a switch for stuffing box monitoring, a temperature
switch or a limit value switch for example.
Digital input 2 (on the alarm module option) can be configured in the
same way.
4 Monitoring of number of strokes
5 Monitoring of number of changes of direction
The two values number of strokes and number of changes of direction
are compared continuously with the limit values which are specified
with the parameters “50. STRK” and “51. DCHG”. The fault message
output responds when exceeded. Both functions can be deactivated
with the parameter setting ”OFF”.
6 Monitoring of the bottom hard stop (valve seat)
7 Monitoring of the top hard stop
Monitoring of the bottom hard stop is activated when the parameter
“52. ZERO” has a value
¸
OFF. Errors of the valve seat can be detected
with this function for example. Exceeding of the limit value may hint at
deposits or foreign bodies in the valve seat. Exceeding the limit value
may be caused by wear of the valve seat. Mechanical maladjustment of
the position feedback may also trigger this error message.
Monitoring takes place every time the valve is in sealing position. The
current position is compared with the one determined during initializa-
tion as a bottom end stop. Activation of the sealing bottom function (pa-
rameter “39.YCLS”) is therefore a prerequisite.
Example: 3% is set as a value. Normally the setting 0% is adopted
when sealed. If a value >3% or <--3% is determined instead, a fault is
reported.