B863–032 Monitored 24 Vdc Input, Quick Start Test
(Original Document)
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Quick Start Test Procedure
This test configures the module as follows: B863 (4 register binary).
Step
Action
1
Stop the controller.
2
Determine which channel and slot location are being used for this module and insert the module.
3
Wire +24 Vdc external power supply to terminal 18, and connect common to terminal 20 on a AS-8535-000 high density connector. Do not connect any other field wiring to the connector.
NOTE: Remove the keying tabs on the AS-8535-000 high density connector prior to installing module.
4
Turn ON the external 24 Vdc power supply. The Field Power light will come ON.
5
I/O Map the module as a B863, four register inputs 30001 ... 30004 binary. Recall that the first two registers are used for real inputs, and the last two registers are error flags.
6
Start the controller.
7
Confirm that the module’s active light is illuminated.
Note: Active on steady = OK. Active blinking = Check the 24 Vdc external power supply voltage and wiring.
8
View the B863 I/O mapped registers, 30001 ... 30004 on the reference screen in binary format.
9
Verify that all the points are zero.
The first two registers, 30001 and 30002 are real inputs. Open inputs to the module reads 0. The second two registers, 30003 and 30004 are error flags. A value of 1 in any of these error flag points indicates a faulty input.
10
Turn OFF the external 24 Vdc power supply, and all error flag points change to 1.
11
Turn ON the external 24 Vdc power supply, and all error flag points change back to 0.
12
To test an input, connect a wire from the +24 Vdc point on the connector terminal 18, and touch the other end of the wire to terminal 1. Bit 1 in 30001 goes from 0 to 1. The error flag for input 1 is found at bit 1 in register 30003. When the input is functional this reads 0.
Application Example 1
The B863 module not only reads 24 Vdc inputs, but it allows you to monitor the health of the input circuits through the use of the input error flags. In the following example, networks allow you to monitor the error flag inputs for maintenance and troubleshooting. If the B863 module is I/O mapped as 30001-30004, then registers 30001 and 30002 are the real world inputs, and 30003 and 30004 become the error flag Inputs.
Comparison of registers 30003 and 30004 to registers 40011 and 40012.
NOTE: 40011 and 40012 must be initialized to zero.
Application Example 2
If a miscompare is detected then output 10 goes ON and 40010 will contain the bit with the error as shown in the following illustration. These error bits are stored in an error table through the R-T function block. The MBIT function block sets the same bit in matrix B so the input at fault is not placed into the error table on every scan.
The following table shows how a failure of input 15 would look in the error table.
B863-032 Input 15 Error Table
Register
Data
40100
0001 ¨ Pointer to Table
40101
0015 ¨ Fault with Input Bit 15
40102
0000
40103
0000
.. .
.. .
40110
0000
The following figure shows matrix A input registers (30003 and 30004) and how a failure of input 15 or bit 15 looks. When the error is corrected, the error table and pointer should be cleared to 0.