Input Data Values; General Status Bits (S0 To S7); Input Data Not Valid Condition - Spectrum Controls 1769 User Manual

Word/Bit 15 14
0 Analog Input Data Channel 0
1 Analog Input Data Channel 1
2 Analog Input Data Channel 2
3 Analog Input Data Channel 3
4 Analog Input Data Channel 4
5 Analog Input Data Channel 5
6 n/a n/a OC5 OC4 OC3 OC2 OC1 OC0 n/a n/a S5
7 n/a n/a O5
NOTE
Chapter 3: Module, Data, Status, and Channel Configuration
Table 3-5 (Input Data File)
13 12 11 10
O4 O3 O2

3.4.1 Input Data Values

Data words 0 through 5 correspond to channels 0 through 5 and contain the
converted analog input data from the input device. The most significant bit, bit
15, is the sign bit (SGN).

3.4.2 General Status Bits (S0 to S7)

Bits S0 through S5 of word 6 contain the general status information for channels
0 through 5, respectively. If set (1), these bits indicate an error (over- or under-
range, open-circuit or input data not valid condition) associated with that
channel. The data not valid condition is described below.

Input Data Not Valid Condition

The general status bits S0 to S5 also indicate whether or not the input data for a
particular channel, 0 through 5, is being properly converted (valid) by the
module. This "invalid data" condition can occur (bit set) when the download of a
new configuration to a channel is accepted by the module (proper configuration)
but before the A/D converter can provide valid (properly configured) data to the
1769 bus master/controller. The following information highlights the bit
operation of the Data Not Valid condition.
1. The default and module power-up bit condition is reset (0).
2. The bit condition is set (1) when a new configuration is received and
determined valid by the module. The set (1) bit condition remains until
the module begins converting analog data for the previously accepted
new configuration. When conversion begins, the bit condition is reset
(0). The amount of time it takes for the module to begin the conversion
process depends on the number of channels being configured and the
amount of configuration data downloaded by the controller.
If the new configuration is invalid, the bit function remains reset (0) and
the module posts a configuration error. See Configuration Errors.
3. If A/D hardware errors prevent the conversion process from taking place,
9 8 7 6
O1 O0 n/a n/a U5 U4 U3 U2 U1 U0
User's Manual Pub. 0300241-02 Rev. A
5 4 3 2 1
S4 S3 S2 S1
3-11
0
S0