72
5.3.10 Adjusting control output setpoints
while displaying time
Direct access to the control output setpoints from
the clock display mode is obtained by operating
the
P
and
Up
push-buttons simultaneously as
shown in Fig 5.3. If the setpoints are not
protected by a security code the control output
setpoint prompt 'OP1: On1' will be displayed. If
the setpoints are protected by a security code,
'COde' will be displayed first. Pressing
P
again
will enable the control output security code to be
entered digit by digit using the
Up
and
Down
buttons to change the flashing digit and the
P
push-button to move control to the next digit. If
the correct code is entered pressing
E
will then
cause alarm setpoint prompt 'OP1: On1' to be
displayed. If an incorrect security code is
entered, or a button is not pressed within ten
seconds, the instrument will automatically return
to the display mode.
Once within the menu pressing the
Up
or
Down
buttons will scroll through all the setpoints. When
the required setpoint is displayed pressing
P
will
reveal the existing setpoint time. This may be
adjusted using the
Up
and
Down
push-buttons
and the
P
button to move control to the next digit.
When the required time has been entered,
pressing
E
will return the display to the setpoint
identification from which another setpoint may be
selected, or the clock may be returned to the
display mode by pressing
E
again.
Each of the two control outputs has two or four
setpoints depending upon whether the output has
been programmed to turn on & off once or twice
in each 24 hour period. – see 5.3.7
Notes:
Direct access to the control output
setpoints is only available when the menu is
enabled - see section 5.3.9
Seconds are always displayed while adjusting the
setpoints.
Fig 5.3 Setpoint adjustment from the clock
display mode
5.4 APPLICATION
Fig 5.4 illustrates a typical application in which a
24 hour clock with a HH:MM format is required in
a Zone 2 hazardous area. To comply with
auditing requirements, the clock is to
automatically synchronised at 12:00 each day.
To prevent accidental adjustment the instrument
programme menu is to be protected by security
code 1112
When the synchronising contact is closed the
BA364ND will display the programmed reset
time, in this application 12:00. When the
contacts open the clock will start running from the
reset time. This contact may be a PLC output
programmed to close at 11:59:58 and to open at
12:00:00
