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SCL type casting and direct addressing

Created by: DirkIV at: 2/19/2008 5:50 PM (3 Replies)

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2/19/2008 5:50 PM	Rate (0)
DirkIV Posts: 5 Rating: (0)	Hi I would like to know how to do two things. The first is to be able to assign a byte to a DB addressed defined as a bool using only symbolic addressing eg. DB1 - SETTING_DB address name type initial value comment 0.0 bool1 bool false 0.1 bool2 boolfalse ... up to 0.7 in scl I would like to assign SETTING_DB.bool1 := B#2#0000_0000; I do not want to assign 0 to every single bit. Is there a way to type cast the first bit of the series to a byte and doing the assignment? next question also related Let's say I have a DB like this DB2 - SETTING_DB_1 address name type initial value comment 0.0 posinteger 0 I want to assign the litteral value W#2#0100_1001_1100_1111 to pos as in pos := W#2#0100_1001_1100_1111; in other words can I type cast the value so that it would be assigned to pos. I do not want to use conversion functions because that swops bytes around. Help would be appreciated
DirkIV Posts: 5 Rating: (0)
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2/20/2008 3:20 PM	Rate (0)
Aret Posts: 2348 Rating: (265)	1. YoucanuseATkeywordlike x_arr : ARRAY [0..7] of BOOL; x_byte at x_arr : BYTE; then if you change bit in X_arr then x_byte would change also and visa versa. 2. Didn't understand what you mean - sorry. Can you exlain more carefully?
Aret Posts: 2348 Rating: (265)
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2/27/2008 9:48 AM	Rate (0)
DirkIV Posts: 5 Rating: (0)	Basically I want to know how you can dereference variables and how you can typecast variables. In pascal for example you could dereference a variable byputting a "&" eg "&var" in front of the variable. And you could type cast it ...not sure but in C, you can type cast by writing "(* vartype varname)". This simplifies coding sometimes. I got around this by direct addressing, which is not an ideal solution, but in the simatic environmet, maybe this is ok.
DirkIV Posts: 5 Rating: (0)
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3/3/2008 8:32 AM	Rate (0)
Aret Posts: 2348 Rating: (265)	Sorry for late answer - internet was unreachable^) AT construction allowstodeclare2variablesofdiffenttypesatonememoryarea.
Aret Posts: 2348 Rating: (265)
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