Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 104)

7–16 Configuration: Scanner Control, Primary Match Table, Discrete I/O
Publication 2755-833
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ATTENTION: Outputs are initially open (off) when
power is first applied to the decoder, and again when
the decoder is powered off.
If a fault condition is detected, the outputs open and the CPU
ACTIVE indicator light turns off.
Source
Field Type Options
Select
A (Default for DS)
B
A|B = A or B (Default for DD)
A–B = Precedent determined
Specifies from which scanner(s) an event can originate and meet the
primary match pattern requirements. For single head decoders,
Scanner A is the default value. For dual head decoders, the default
value is A|B, which means that the decoder will accept input from
either A or B to create a match. Other options include Scanner B, or
precedent determined (A–B).
When set to A–B, the decoder will use the first input from either
Scanner A or Scanner B to establish a precedent for all following
inputs. If, for example, the first input comes via Scanner B, then only
data from Scanner B will be matched from that point on.
Output Condition
Field Type Options
Select
None
Read Package
No–Read Package
Match-Complete
Match-Entry
Read and No-Match
No-Read or No-Match
Auto Load at Startup
Buffer Full
Buffer Overflow
Auto Load (INPUT)①
① Applies only to module position 8.
Defines the condition that will activate a specified output. The
default is None, which means a condition is not defined for the
output.
The available output conditions appear below. Select the output
condition appropriate for your application.