f. Before you define your “EXECUTE” function, you should first set up its
“trigger bit.” For this purpose you should select a currently unused bit
from among your system’s
first 32 bits.*
g. Enter a command of
LGT x = r [CR]
where “x” is again the number of the channel you calibrated in Section 10,
above, and “r” is the number of the selected trigger bit (it must be a num-
ber from 0 through 31).* As you learned in the previous section, this com-
mand automatically assigns a “logic source” of “N
ON
LATCHING LIMIT
LOGIC” to Bit No. r.
h. Now command
EXU r = BIT898=1:CHN150=0 [CR]
The command string specified by an EXU command can take up to 32
ASCII characters, including spaces; individual commands are separated
by colons.
i. Increase the load applied to Channel No. x’s source transducer until it is
greater than the high-limit value you entered in Section 13, Step b, above.
j. As soon as Channel No. x’s high limit is violated, Bit No. 898 should auto-
matically “go high” and Channel No. 150 should automatically report a
value of “0.” Use the
BIT command to verify that the state of Logic Bit No.
898 is now “1.” Observe the displayed reading of channel No. 150 to veri-
fy that it is in fact “0.”
k. Now enter a command of
BIT 897 = 0 [CR]
l. Keep the “high violation” load on the transducer, and enter a command of
EXU /r = CHN150=25:BIT897=1 [CR]
where “r” is again the number of the selected trigger bit. This command
instructs the system to
• load Channel No. 150 with the number “25,” and
• set Logic Bit No. 897 to “Logic 1”
when Logic Bit No. r “goes low”—i.e., when the transition of Bit No. r
from
“Logic 1” to “Logic 0”
is perceived.
m. Remove the transducer load. Channel No. 150 should now read “25.”
n. Use the READ form of the
BIT command to verify that the state of Logic Bit
No. 897 is now “1.”
o. You might now want to set up and verify an
EXU or EXU/ function that
increments the reading of Channel No. 150 by “1,” and also “locks” (or
“freezes”) a given real channel (No. “y”)**:
A - 24
SETUP OF EXECUTE FUNCTIONS
“O
NTHE
A
IR
” (A-S
IZED
)
* This assumes that your mainframe has been initially set to employ the first two bit groups
(Bits 0 through 31) for the purpose of triggering EXECUTE (EXU) command strings. It is
possible to assign the system’s EXU statements to the bits of any two bit groups (which
need not be contiguous) by means of the EXECUTE BASE GROUP (XBG) command, as
explained in Section 2.K.2 of the System 10 Guidebook.
** The LOCK (LOK) command can be used to inhibit the automatic updating of all channels,
one selected channel, or a selected range of channels. To “unlock” (resume normal
updating) of Channel No. y, you must enter an UNLOCK (UNL) command of UNL y [CR].
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