•
Navigate between pages by clicking the left and right arrows within the page navigation area in the top right corner
of the PC Interface
•
Modify properties of all blocks by either double-clicking a block or by selecting a block and clicking Edit under the
Properties table
•
Delete any block or connection by selecting the item and then either hitting the Delete key on your keyboard or
clicking Delete under the Properties table
NOTE: There is no confirmation of the object deletion. You may undo the deletion by clicking
Undo.
By default all inputs added on the Equipment view are placed on the Functional View to the first available placeholder in
the left column. There are two ways move signals from one page to another. To do so, perform one of the following steps:
1. Add a Reference to the block located on a different page—click any of the empty placeholders in the middle area,
select Reference and select the block that is on the next page. Only blocks from other pages can be added as a
Reference.
2. Re-assign page—on the page where you want to keep the configuration, move one of the blocks to any of the
placeholders in the middle area. Go to the page which contains the block that needs to be moved. Select the block
and change the page assignment below the Properties table.
4.8.1 Logic Blocks
Logic Blocks are used to create Boolean (True or False) functional relationships between inputs, outputs, and other logic
and function blocks. Logic Blocks accept appropriate safety inputs, non-safety inputs, or safety outputs as an input. The
state of the output reflects the Boolean logic result of the combination of the states of its inputs (1 = On, 0 = Off, x = do
not care) .
CAUTION: Inverted Logic
It is not recommended to use Inverted Logic configurations in safety applications where a hazardous
situation can occur.
Signal states can be inverted by the use of NOT, NAND, and NOR logic blocks, or by selecting "Invert Output" or "Invert
Input Source" check boxes (where available). On a Logic Block input, inverted logic treats a Stop state (0 or Off) as a "1"
(True or On) and cause an output to turn On, assuming all inputs are satisfied. Similarly, the inverted logic causes the
inverse function of an output when the block becomes "True" (output turns from On to Off). Because of certain failure
modes that would result in loss of signal, such as broken wiring, short to GND/0 V, loss of safeguarding device supply
power, etc., inverted logic is not typically used in safety applications. A hazardous situation can occur by the loss of a stop
signal on a safety input, resulting in a safety output turning On.
AND
(US)
(EU)
Input 1
Input 2
Output
0
x
0
x
0
0
1
1
1
The output value is based on the logical AND of 2 to 5
inputs.
Output is On when all inputs are On.
OR
(US)
(EU)
Input 1
Input 2
Output
0
0
0
1
x
1
x
1
1
The output value is based on the logical OR of 2 to 5
inputs.
Output is On when at least one input is On.
XS/SC26-2 Safety Controller
24
