User's Manual

Series 4000 Operation
MTU Installation Requirements 5
Alarms
In addition to the tamper alarms, the MTU may also be configured to send the
following alarms to the NCC:
Last Gasp
The MTU will regularly report battery voltage values to the NCC. When this value
falls below a specified value, the NCC will display a Low Battery notification.
Aclara recommends changing the battery promptly when a low battery alarm is
received. Please see Maintenance on page 35 for more information.
Pressure
The user can configure the MTU to return a pressure alarm whenever the pressure
reading from the instrument is outside a given range. If enabled, the MTU will also
begin operating in Trend Mode until the pressure returns to the desired range.
Please refer to Trend Mode on page 5 for more information.
Serial Communication Problems
The MTU will return an alarm to the NCC if basic communication with the
instrument is not possible. This will most likely be due to incorrect instrument
configuration.
Data Encryption
The Series 4000 MTU units support the encryption of user sensitive data. When
data encryption is enabled, all readings and data packets except for alarms will be
encrypted prior to transmission.
Trend Mode
Trend Mode is an operating mode of the MTU that, when enabled, will begin
automatically sending pressure values (and corresponding time stamps) at regular
intervals whenever a pressure or other configured alarm is received from the
instrument.
Trend Mode may also be initiated or canceled directly from the NCC. Using the
default settings for Trend Mode, the MTU will record the pressure once a minute
and transmit these readings once every six minutes to the NCC.
Read Interval
The user may configure Trend Mode to read the pressure either once a minute or
once every five minutes.
DRAFT