15
Watchdog Timer
When enabled, the Watchdog Timer will disable the outputs if the card is not accessed by the
controller within 150 ms. When disabled, the Watchdog Timer has no effect on the card's
operation. For safety-critical applications, this variable must be enabled.
Integer Error Detection
The Error Detection input is an Int Variable that can be used to detect an I/O card failure.
NetArrays assigns a default Tag to this variable when the card is added to the I/O configuration.
A Card Timeout Error (Bit 0) will set the Error Latch bit (Bit14), which will remain set until this bit is
cleared to zero by an operator. While the Error Latch is set, the card will be offline and the target
node will not attempt to communicate with it. Note that most cards do not use all the status bits
shown. Any unused bits will always equal zero.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ERR
LTCH
FAULT
ERR
DATA
ERR
DATA
INV
CARD
ID
CARD
ERR
CBL
ERR
LOOP
BACK
TIME
OUT
Bit 14 Card Error Latch
This status bit indicates that a Card Timeout Error occurred on the I/O card, and that it
has been taken offline. The card will not be initialized or placed online until this bit is
cleared in the project program or operator intervention.
If this bit is set, it must be cleared to return the card to operation. The correct way to
clear this bit is to select the card’s icon in the I/O configuration Form while NetArrays is
operating in Debug mode and answer “Yes” to the Enable prompt. See I/O Card Status
and Control. (It is also possible to change the value of this variable by forcing an Integer
Bit Variable object, with Bit 14 selected in the object's properties, to zero.
Do not
clear
the entire Error Detection Integer Variable to zero.)
Bit 10 Fault Test Error
This status bit indicates that a fault insertion test was performed, and a channel did not
detect the error.
Bit 9
Backplane Bus Data Error
This status bit is applicable only to I/O cards with Backplane Bus data checking
capability. It indicates that a data error was detected in a data or command transfer to or
from an I/O card.
Bit 8
Data Invalid
This status bit indicates that the I/O card is not ready to send valid data.
Bit 7
Card ID Does Not Match I/O Configuration
This bit indicates that the ID code read from the I/O card does not match the card type
specified in the NetArrays I/O configuration.
Bit 6
Card Specific Error
This bit indicates a PLD Error.
Bit 5
Cable Detect Error
This bit indicates that one or more of the cables are not connected to the I/O card or
between the I/O card and the termination block.
Bit 4
Loopback Error
This bit indicates that the card has failed a loopback test. The actual output from the card
does not equal the expected output.
