BEKA BA354E, Руководство пользователя

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10.2.14 Adjusting alarm setpoints from the
display mode.
Access to the alarm setpoints from the Rate
Totaliser display mode is obtained by operating the
P and ▲ push buttons simultaneously as shown in
Fig 14. If the setpoints are not protected by a
security code the alarm setpoint prompt 'SPx1' will
be displayed. If the setpoints are protected by a
security code, 'Code' will be displayed first.
Pressing
P again will enable the alarm security
code to be entered digit by digit using the ▲ and
▼ 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 cause alarm
setpoint prompt 'SPx1' to be displayed. Pressing
the ▲ or ▼ button will toggle the display between
the two alarm setpoint prompts 'SPx1' and 'SPx2'.
If an incorrect security code is entered, or a button
is not pressed within twenty seconds,
the Rate
Totaliser will automatically return to the display
mode.
Fig 14 Setpoint adjustment from the display mode
To adjust an alarm setpoint select 'SPx1' or 'SPx2'
and press
P which will reveal the current setting.
Each digit of the setpoint may be adjusted using
the
▲ and ▼ push-buttons, and the P button to
move control to the next digit. When the required
setpoint has been entered, pressing
E will return
the display to the 'SPx1' or 'SPx2' prompt from
which the other setpoint may be selected, or the
Rate Totaliser may be returned to the display
mode by pressing
E again.
Notes:
1. With the Rate Totaliser in the display mode,
direct access to the alarm setpoints is only
available when the AC5P
menu is enabled -
see section 10.2.13.
2. While the alarm setpoints are being adjusted
from the display mode totalisation is
suspended, any flow occurring during this
time will not be recorded.
3. The setpoint identification changes depending
on the type of alarm. If alarm 1 has been
conditioned by the ‘tYPE’ function to operate
on the rate display the setpoint will be
identified as ‘5Pr1’, if operating on the total
display it will be identified 5Pt1. Similarly for
alarm 2.
10.3 Display backlight
The BA354E loop powered Rate Totaliser can be
supplied with a factory fitted backlight that may be
loop or separately powered.
When loop powered the backlight produces green
background illumination enabling the display to be
read at night or in poor lighting conditions. No
additional power supply, intrinsic safety interface or
field wiring are required, but the Rate Totaliser
voltage drop is increased. When separately
powered the backlight is brighter, but an additional
intrinsic safety interface and field wiring are
required.
Fig 15 Terminals for optional backlight
10.3.1 Loop powering the backlight
The backlight is loop powered by connecting it in
series with the Rate Totaliser’s 4/20mA input as
shown in Fig 16, which increases the maximum
Rate Totaliser voltage drop from 1.2 to 5V.
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