B875-111 Analog Input, Module Configuration

Overview

The B875-111 module is shipped from the factory with the 1—5 V range with 0—4095 output format (standard), one sample averaged, and voltage inputs, 8 channel (B875-111)–i.e., all DIP switches to the right. If necessary, reset the module configuration switch and the five-position DIP switch based upon the application requirements prior to installation.

Refer to the illustration of the module configuration switch, below.

Module Configuration Switch with DIP Switches

The following illustration shows the module configuration switch and DIP switch settings for the B875–111 module.

B875–111 analog input module, module configuration switch and DIP switch settings

Use the following table to determine the functions for each switch.

Switches	Functions
SW1	Input Range
	For Bipolar ( 10 V, 5 V 20 mA):SW1=L
	For Unipolar (0—10 V, 0—5 V, 0—20 mA, 1—5 V, 4—20 mA): SW1=R
SW2	Input Range
	For Offset (1—5 V or 4—20 mA): SW2=R
	For No Offset (All other Ranges): SW2=L
SW3 & SW4	Output Formats (refer to the following table for resolutions)
	For Standard (0000—4095): both SW3 and SW4=R
	For Elevated (4096—8191): SW3=L and SW4=R
	For Full Resolution (Raw Binary): SW3=R and SW4=L
	For Decimal (0001—9999): both SW3 and SW4=L
SW5 & SW6	Samples to Averaged
	For 1 Sample: SW5 and SW6 both R
	For 8 Samples: SW5=L and SW6=R
	For 16 Samples: SW5=R and SW6=L
	For 32 Samples: SW5 and SW6 both L
SW7	Input Types
	For 8 Differential (B875):SW7=R
	For 16 Single Ended (B877): SW7=L
SW8	Input Ranges
	For 10 V (10 V or 0—10 V): SW8=L
	For 5 V (All Others): SW8=R

Output Format Selection

The following table provides the output formats and their resolution relationships:

Output Format	Under Range	Normal Range	Over Range	Resolution	Actual Format
Standard	0000	0000—4095	4096	12 bits	Raw binary, unsigned
Elevated	4095	4096—8191	8192	12 bits	Raw binary, unsigned
Full Resolution	Bit 16=1 Bit 15=1	Bit 16=0 Bit 15=0 1—7499	Bit 16=1 Bit 15=0	Bipolar=1/15000 counts Unipolar=1/7500 counts Offset=1/6000 counts	*Raw binary and two flags
Decimal	Bit 16=1 Bit 15=1	Bit 16=0 Bit 15=0 1—9999	Bit 16=1 Bit 15=0	Bipolar=1/1000 counts Unipolar=1/7500 counts Offset=1/6000 counts	Raw binary and two flags 1—9999 counts 1—9999 counts
*When an under or over range condition exists, the output word contains the applicable flag and the under or out-of-range value.

Standard output format is raw binary output, 0—4095 counts. Under range is 0000 and over range is 4096.

Elevated output format is raw binary output, 4096—8191 counts. Under range is 4095 and over range is 8192.

Full resolution output format provides the true resolution of the module which depends on the input range.

Bipolar inputs produce an output of 0001—14,999 counts

Unipolar inputs produce an output of 0001—7499 counts

Unipolar and offset inputs produce an output of 0001—5999 counts

In the full resolution format, out-of-range values of 2.4% may be read to the specified accuracy of the module. They can be read in this manner. When an out-of-range condition occurs which is over range the MSB (bit 16) is set to 1. If an under range occurs the second MSB (bit 15) is also set to 1. The remaining 14 bits give the absolute value of the amount over or under range. For example, for a unipolar input of 5.120 volts the output would have bit 16 set to 1. The remaining output bits equaling the raw binary representation of 120 millivolts. Any input above the 0.120 volts in this range willnot be within the specified accuracy of the module.

Decimal output format allows scaled outputs to provide 0001—9999 counts full scale. This format does not indicate the true resolution of the module. For bipolar inputs the output is scaled down and for unipolar inputs the output is scaled up. This format also reports out-of-range values in the same manner as the full resolution mode.

NOTE: For unipolar and unipolar with offset image ranges, the process of scaling the lower resolution output values to the 1—9999 output format creates the possibility of missing codes due to rounding off of numbers in the micro controller.

NOTE: When applying power to the equipment, or after a reset, the module transfers 4000 Hexadecimal during its internal reset, and initialization time until valid data is ready to be transferred. (4000 Hexadecimal corresponds to the second MSB=1, all other bits=0).

Input Selection

First, locate the four access holes on the left side of the module. These holes allow access to three four-position and one five-position DIP switch.

Next, set switch position 5 (SW5) of the five-position DIP switch found in the bottom access hole on the left side of the module, to select the input range. This switch must correspond to switch position 8 (SW8) of the eight-position module configuration DIP switch. SW5 and SW8 settings must be identical.

NOTE: For switch SW5, the input ranges are as follows:

For 10 V (10 V or 0—10 V) place SW5 to the left.

For 5 V (all others) place SW5 to the right.