Rockwell Automation Allen-Bradley 1769-IF4, Руководство пользователя

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Publication 1769-UM002B-EN-P - July 2005
4-20 Module Data, Status, and Channel Configuration for the Output Modules
1769-OF8C and -OF8V Over-Range Flag Bits (O0 through O7)
Word 1, bits 0, 4, 8, and 12, and Word 2, bits 0, 4, 8, and 12 contain the
over-range bits for channels 0 through 7. When set, the over-range bit
indicates that the controller is attempting to drive the analog output above its
normal operating range or above the channel’s High Clamp level (if clamp
limits are set for the channel). However, the module continues to convert
analog output data to a maximum full range value if clamp levels are not set for
the channel.
If alarm latching is not enabled for the channel, the bit is automatically reset
(0) by the module when the over-range condition is cleared or the commanded
value no longer exceeds the high clamp (the output is commanded to return to
within the normal allowed range). The over-range bits apply to all output
ranges. Refer to Table 4.17 1769-OF8C Valid Output Data Table on page 4-33
and Table 4.18 1769-OF8V Valid Output Data Table on page 4-34 to view the
normal operating and over-range areas.
1769-OF8C and -OF8V Under-Range Flag Bits (U0 through U7)
Word 1, bits 1, 5, 9, and 13, and Word 2, bits 1, 5, 9, and 13 contain the
under-range bits for channels 0 through 7. When set (1), the under-range bit
indicates that the controller is attempting to drive the analog output below its
normal operating range or below the channel’s Low Clamp level (if clamp
limits are set for the channel). However, the module continues to convert
analog output data to a minimum full range value if clamp levels are not set for
the channel.
If alarm latching is not enabled for the channel, the bit is automatically reset
(0) by the module when the under-range condition is cleared or the
commanded value no longer exceeds the low clamp (the output is commanded
to return to within the normal allowed range). The under-range bits apply to all
output ranges. Refer to Table 4.17 1769-OF8C Valid Output Data Table on
page 4-33 and Table 4.18 1769-OF8V Valid Output Data Table on page 4-34
to view the normal operating and under-range areas.
1769-OF8C and -OF8V Diagnostic Bits (D0 through D7)
Word 1, bits 3, 7, 11, and 15, and Word 2, bits 3, 7, 11, and 15 contain the
open-circuit diagnostic bits for input channels 0 through 7. When set (1), these
bits indicate a broken output wire or high load resistance. These bits are always
cleared (0) for the 1769-OF8V module since open-circuit diagnostics do not
apply for analog voltage outputs.