Rockwell Automation 1794-APB/B FLEX I/O PROFIBUS Adapter Module User Manual - Manual (Page 74)

2–54 How Communication Takes Place and I/O Image Table Mapping
Publication 1794ĆUM057B-EN-P - November 2001
Definition
Decimal Bit
(Octal Bit)
Word
Word 7 continued
Bits 10-11
(12-13)
Request for hold outputs (Q). - Channel request bits that instruct an output to hold
its output level when EN transitions from 0 to 1 to 0. When EN is 0, outputs go to a
safe state dictated by S1/S0. When EN returns to 1, the outputs will hold their level
until the output data equals the output level. P0-P3 indicates channels holding.
Output read back data shows what level is being held. Q0 = bit 08 (10) = channel 0;
Q1 = bit 08 (10) = channel 1, etc.
Bit 12 (14) Interrupt Toggle bit (IT) - This bit, when set (1), permits interleaving of module
interrupts ensuring exchange of critical data when channels are configured for their
fastest update times. RTSI and no low pass filter" must be 0 in order for the module
to recognize this feature. This groups data update rates for all channels to the
slowest configuration setting of any of the channels. In addition, channel update rates
for all channels with a 7.5ms update rate are reduced to 5.0ms. When reset (0), real
time sampling and filter features are enabled.
Bit 13 (15) Transparent bit (TR). - This bit, when set to 1, permits configuration to be changed
without using the IC bit.
Bit 14 (16) Set to 1.
Bit 15 (17) Initiate Configuration bit (IC). - When set (1), instructs the module to enter
configuration mode. Present configuration data prior to or coincident with IC being
set. Once IC returns to 0, additional configuration information is ignored.
Word 8 Bits 00-15
(00-17)
Not used