Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller CUSTOMIZATION GUIDE - Manual (Page 9)

2.2 Types of Programs
Unlike other MICRO-DCI instruments, the 53MC5000 Controller supports several types of F-TRAN
programs.
2.2.1 Control F-TRAN
These programs are used to program the actual control strategy. Up to 20 different user written
control F-TRAN programs can be stored in the controller. When they are stored, each one is as-
signed a Function Index (FIX) number. These numbers may be any number between 2 and 255 ex-
cept for 90 - 99 which are reserved for special Fischer and Porter use. The user selects the
program to run by setting the FIX parameter, B00, to the desired value. The selected program will
then be executed at a rate specified by the Scan File parameter (B03). This parameter specifies
the rate in 50 millisecond increments. For example, if B03 is 2, the program will execute every 100
milliseconds (ie 10 times per second). If the program is so long that it cannot be completed in the
allotted time, the Scan FIle Overrun counter (B04) will be incremented and the program will con-
tinue to completion, skipping a scan. The user should increase the Scan File if overruns are com-
mon. Control F-TRAN programs can use any of the statement type listed in the following sections
except for the Display Statements.
2.2.2 Display F-TRAN
These programs are used to program custom displays. Up to 70 different user written display F-
TRAN programs can be stored in the controller. When they are stored, each one is assigned a Dis-
play Index (DSPL) number. These numbers may be any number between 1 and 255. If the user
loads a display program with the same number as a standard display, the users display will be
used.
The controller chooses the display program to use by examining the Display Index B05. The se-
lected program will then be executed at a rate specified by the Display Scan Index parameter
(B06). This rate at which the display program will run and update the display is then 50ms * B03 *
B06. For example, if B03 is 2 and B06 is 2, the display will update every 200 milliseconds (ie: 5
times per second). If the program is so long that it cannot be completed in the allotted time, the Dis-
play Overrun counter (B07) will be incremented and the program will continue to completion.
Display programs can process display statements in addition to the standard F-TRAN algebraic
and flow control operands, operators and statements. Display statements control the placement
and appearance of various text and graphical elements on the display screen. Section 2.4.5.11
explains the various display statements.
In addition to the display statements two datapoints are intimately associated with display appear-
ance. They are B09 and L77. The CHRSET atom (B09) controls both the destination port and
character appearance of text when the PRINT statements are executed. See PRINTn description
for details on the character sets available.
The DFC atom (L77) indicates whether or not the display statements run time translator should be
active. Display F-TRAN supports two display screen resolutions, 48x96 elements and 96x192 ele-
ments. Placement and graphical statement values are defined in terms of these elements. To elimi-
nate the need to write separate programs for both resolutions a translator is built into the run time
processing. When the translator is active (L77 = 0) it assumes all display statements are based on
a 48x96 element reference. If a HiRes display (96x192 element) is present and enabled (L76 = 0)
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