Rockwell Automation 2706-M1 MESSAGEVIEW 421 HARDWARE MANUAL - Manual (Page 64)

4–4 Running Applications
Publication 2706–816
The application determines the maximum length of the ASCII entry
field, from 1 to 32 characters.
A MessageView terminal supports a maximum of 10 embedded
variables per message. Each message may have up to 100 characters
(combined text, graphics and variables).
Messages on a 421N or 421F terminal (or a 421D terminal with
supporting firmware) may contain numeric entry variables that
allows an operator to enter data manually. The application sets the
format and range of data that can be entered, as indicated in the
message itself.
An example of a typical message with a data entry variable is:
ENTER DESIRED
TEMPERATURE IN DEG F Numeric entry variable
displayed here
Numeric data entry supports the following data types:
Variable Data Type Maximum Range ➀
Bit 0 or 1
Unsigned Integer 0 to 65535
Signed Integer –32768 to 32767
Unsigned BCD (4 digit) 0 to 9999
➀ The application may restrict the actual range of data that may be entered in a given
variable, except for Bit type.
Numeric data entry values may have:
•
fixed, floating (keypad) or no decimal point
•
different field widths (1 to 12 digits)
•
scaled data
The terminal can scale the data entered by the operator if this option
is specified in the application. Scaling allows an operator to enter
values in engineering units such as
_C, psi, or lbs. while the terminal
converts them to machine control values. Scaling is described in the
section starting on Page 4–6.
A MessageView terminal supports a maximum of 10 embedded
variables per message. Each message may have up to 100 characters
(combined text, graphics and variables).
Messages with
Numeric Entry Variables