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Rockwell Automation 1794-APB/B FLEX I/O PROFIBUS Adapter Module User Manual User Manual

Page 67

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2–47

How Communication Takes Place and I/O Image Table Mapping

Publication 1794ĆUM057B-EN-P - November 2001

Definition

Decimal Bit

(Octal Bit)

Write Words

Word 7

Bit 00-03

Channel calibration selection bit. When this bit is set (1), the channel can

be calibrated using the calibration clock bit (CK). Bit 00 corresponds to output

channel 0, bit 01 corresponds to output channel 1, it 02 corresponds to output

channel 3, bit 03 corresponds to output channel 4

Bit 04

Gain/Offset selection bit (GO). - When this bit is cleared, a 0 to 1 to 0

transition of the CK bit performs on offset calibration. When this bit is 1, the

module is directed to do a gain calibration.

Bit 05

Calibration clock bit (CK). - When this bit is set to 1 (calibration mode), the

calibration coeffiicient for the selected channels is accepted. When this bit is

reset (0), the accepted calibration coefficients for the selected channels are

stored, applied, and the calibration mode exited. Monitor status bits DN and

BD for succesful calibration.

Bit 06

Quick Calibration bit (QK). - Normally reset (0). When this bit is set (1)

during a calibration sequence, the calibration coefficient is stored to all

related configurations for the selected channels. NOTE: Although this method

of calibration quickly calibrates the selected channels, they will not be within

the rated accuracy of the module.

Bit 07

Revert to defaults bit (RV). - Normally reset (0). When set (1) during a

calibration procedure, default values for selected channels are used for the

calibration coefficient. NOTE: They will not be within the rated accuracy of the

module.

Bits 08-11

(10-13)

Request for hold outputs (Q). - Channel request bits that instruct an output

to hold its output level when EN transitions from 1 to 0 to 1. 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, the configuration is applied and any subquent

configuration information is ignored until IC is toggled.

Words 8 and 9

Bits 00-15

(00-17)

Not used