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SYSTEM
SUPPORT SERVICES 11046 State Road 52, Hudson, FL 34669 ● (727) 243-3656 |
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SYSTEM
SUPPORT SERVICES 11046 State Road 52, Hudson, FL 34669 ● (727) 243-3656 |
| Product(s) Affected: | Multi-level Supervised Input Module |
| Model or Part Number(s): | 30-0121-2 |
| Release Date: | November 30, 1994 |
| Subject: | Firmware Rev. C and Part Number Change |
Several sites have had difficulty installing the Revision A1 or B firmware and resistor change to the 30-0121-2 Multi-level Supervised Input Module (COMPUTROL FTB # 6, November 7, 1988.)
The Revision A1/B release corrected several bugs in the firmware, and made the board impervious to defeat by varying the loop resistance. This latter improvement was accomplished by tightening the tolerances on the alarm windows, and by implementing supervisory states between each valid normal or alarm state.After installing the change, spurious supervision alarms have sometimes occurred. These nuisance alarms are usually caused by noise on the supervised loops, by faulty switch contacts at the monitored point, or by loose connections in the field wiring.
In many cases, the spurious alarms can be eliminated by inspecting and testing the switches and field wiring, and correcting any problems found. In other cases, however, the cause of the nuisance alarms cannot be completely eliminated.
In response to requests from the field, SYSTEM SUPPORT SERVICES has released Revision C of the firmware for the 30-0121-2 Multi-level Supervised Input Module. Also, the part number of the EPROM has been changed. the new part number is 80-2200C, replacing the old 86-2200 number.
The revision involves loosening the tolerances on the normal and alarm windows to improve noise immunity, while at the same time maintaining the supervisory states which maintain the board's resistance to tampering. Figure 1 lists the loop resistance crossover points for the Revision A1/B and for the Revision C firmware. Note that these are theoretical boundaries, and actual trip points will vary based on resistor tolerances, and variations in circuit parameters and current source adjustment. Measured values should be within 50 ohms of these values, however.
Figure 1
Loop Resistance Ranges
for Rev. A1/B and Rev. C Firmware
As can be seen from the above figure, the detection ranges for the normal and alarm states have been increased, and the intermediate supervisory ranges have been decreased. This change will provide greater tolerance to noise on the supervised loops, and allow for more error in the total loop resistance due to long cable runs, loose connections, and faulty switches.
It should be noted, however, that installing this firmware change is NO SUBSTITUTE for proper field wiring maintenance.
If excessive supervisory alarms are encountered on boards with the Revision A1 or Revision B firmware installed, then performance can be significantly improved by installing Revision C firmware.
Revision C and older boards (with Revision A and older firmware) must first be upgraded to Revision C1 by replacing R19 with a 1.27K ohm, 1/4 Watt, 1% resistor. Revision C firmware WILL NOT OPERATE in Revision C and older boards. If the board to be upgraded is Revision C or older, contact SYSTEM SUPPORT SERVICES about upgrading the assembly to Revision C1.
There are three alternative approaches to implementing the Revision C firmware update:
To have SYSTEM SUPPORT SERVICES repair, test and update the modules as necessary, contact Customer Service for a Return Material Authorization number. Have available the part number of the module to be repaired and upgraded, and the quantity.
To order individual copies of the firmware, or to order a site license, please use the following part numbers:
| FIM PART NUMBER | INDIVIDUAL EPROM PART NUMBER | SITE LICENSE PART NUMBER |
|---|---|---|
| 30-0121-2 | 80-2200C | 88-2200C |
E-mail: service@sysupport.com
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Revised: April 24, 2006 .