Function library
Function blocks
3.5.12 BCD decade switch (BCD)
3−126
l
EDSVS9332P−EXT DE 2.0
With handshaking, minimum wiring
Set BCD mode = 1.
BCD_C
B C D x - N E W - D A T A
t
B C D x - D A T A x
B C D x - R E A D
2 n d c y c l e 3 r d c y c l e 1 s t c y c l e1 s t c y c l e
( 4 i n p u t s )
( I n p u t )
( O u t p u t )
Fig. 3−79 Sequence of handshaking
Function
l The superimposed control (e.g. PLC) determines the time of data transmission.
l After the acceptance signal has been sent from the control to BCDx−READ the BCD is read.
– The signal must be sent for every BCD.
– The reading routine of the FB BCD remains in waiting position until the data transmission is
started.
The BCDs are read in the following sequence:
1. Sign
2. BCD 1
3. BCD 2
4. etc.
Transmission sequence of a BCD:
Input/output Signal Function
BCDx−DATA1 ...
BCDx−DATA4
Generating data for the first or next BCD via PLC.
BCDx−NEW−DATA HIGH Enables the transmission for the next BCD.
BCDx−READ LOW−HIGH edge Reading of the BCD data to the FB BCD.
BCDx−NEW−DATA LOW Inhibits the transmission for the next BCD.
BCDx−READ LOW Set via PLC.