Rockwell Automation 2706-MB1 MESSAGEVIEW 421 SOFTWARE MANUAL - Manual (Page 170)

7–49 Creating Messages
Publication 2706-817
Function Key: Select a Function key from the Function Key list
box. After all its attributes are set, you may select another Function
key and set its attributes.
Type: Select the Type list box and highlight the type needed.
•
None: the Function key is not used.
•
Momentary: changes state (0 to 1 or 1 to 0) when pressed and
released. Changes back to its initial state after the defined Hold
Time has expired.
•
Maintained: changes state (0 to 1 or 1 to 0) when pressed and
remains in the changed state when released.
– If the message is in Jog mode, the Function key returns to its
original state when pressed and released again.
– If the message is in non-Jog mode, a new message must be
triggered and displayed with the same Function key enabled,
so the key can be pressed and released again.
•
Latched: changes state (0 to 1 or 1 to 0) when pressed and
remains in the changed state when released. To return the
Function key to its original state, the logic controller must set a
handshake bit. See Page 4–24 for a discussion of Latched
Function Keys and handshaking.
Initial State: If a Maintained Function Key was selected under
Type, select Open or Closed initial state. This option is greyed out
when another type is selected. A Maintained Function Key toggles
between two states, so the state on powerup does not need to be the
same as the Contact Open/Closed state.
Contacts: Select either Normally Open or Normally Closed,
depending on how the Function key is to be used.
Hold Time: If a Momentary Function Key was selected under Type,
select a Hold Time. This option is greyed out when another type is
selected. Hold Time can be 0, 50, 250, 500, 750 or 1000
milliseconds; default is 500 ms.
The terminal holds the Function Key bit set/cleared for the Hold
Time, even if the key is physically released at once. The Hold Time
should be longer than the scan time of the controller, to ensure that
the bit is read at least once.