Rosemount 3491, Reference Manual, Page: 65 / 152

Reference Manual
00809-0100-4841, Rev. AA
May 2007
4-33
Rosemount 3490 Series
Digital Inputs IN1 and IN2
Digital inputs IN1 and IN2 can be individually set-up to perform an action
whenever they are activated.
NOTE:
Digital input status icons are shown on the left-hand side of the Primary
Display: o = inactive or
= active.
In addition, parameter D835 shows the status of the inputs: active (1) or
inactive (0). First digit represents IN1.
How to allocate an action to IN1 or IN2:
1. Navigate to:
MAIN MENU / SETUP / [CONTROL UNIT /] DIGITAL INPUT
2. Select a 'Digital Input' menu: Action, Delay or On-State.
3. Allocate a function by editing the Action Select parameter P340 (for IN1)
or P345 (for IN2).
Table 4-10 lists all the options and explains their purpose
4. If you require a delay before an action is performed, edit the Delay
parameter P341 (for IN1) or P346 (for IN2).
The parameter value format is m:s (minutes and seconds).
5. To change the logic of the input for triggering an action, edit the On State
parameter P342 (IN1) or P347 (IN2).
Options are "Closed" (active when voltage-free contact is closed: default
setting) and "Open" (active when open).
Table 4-10. Digital Input Actions
Action Action that occurs while digital input is active
Free Digital Input has no allocated action. (Default).
Alarm Forces an alarm condition, which is indicated if specified in the ALARM
menu. For information about alarms and features they affect, see Section
“About Alarms“ on page 4-60.
Go Offline Changes the operating mode to off-line (open padlock).
Hold totaliser Freezes the internal totaliser.
Hold MCU PV Prevents the PV value (D800) from being updated while the digital input is
active.
Suppress Alarm The Alarm relay is held on. If the digital input is active when an alarm
condition is present, a message is displayed indicating the alarm is being
overridden.
Display Msg Displays a user-defined message (P241).
(1)
(1) SETUP / [MCU CONTROL UNIT /] Duty(Mode)/ Message.
Log Input When the next logging interval elapses, flag the data logged as a 'bad
sample' if the digital input has been active. (Model 3493 only)
Pump-down
(2)
(2) Pump-down feature available on models 3491 and 3492 only.
Invoke a pump-down operation
(see Section “Pump-down (Models 3491 and 3492 only)“ on page 4-54).
Lock Params Prevent 'P' prefixed parameters from being edited.
Protect totaliser 1 Protect totaliser 1 from being reset.
Reset totaliser 2 Reset totaliser 2. (Models 3492 and 3493 only).