Sample sequencer, Appendix g – SentrySafe SPD 5.5.5 User Manual
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Sample Sequencer
Appendix G
Appendix G 
 
Retrofitting a Plug-in (Internal) Track & Hold Board in the Field 
 
Please, follow the below procedure if a plug-in (internal ) track & hold upgrade kit was purchased to 
retrofit an existing Sample Sequencer in the field. 
 
The upgrade kit should contain one or two (if ordered) plug-in track & hold boards, one 3 Amp fuse, 
a new microprocessor and a 3 Amp 6 VDC power supply. If the kit with two boards was received, 
an enclosure and cable for remote mounting of your existing valve relay board is also included. A 
new microprocessor is also included. 
 
Procedure 
 
1. 
Disconnect power.
 
2. 
Disconnect wires and remove signal switching board. This board is the left-most board as 
viewed from rear of the Sample Sequencer (See Figure 17). You may store this board 
because it is not used in conjunction with the plug-in track & hold board feature. 
 
3. 
If two plug-in track & hold boards must be installed, disconnect wires and remove the valve 
relay board (located in the center as viewed from rear). Install this board in the remote 
enclosure provided with your track & hold retrofit kit. The valve board must be located 
remote from Sequencer in order to install two plug-in track & hold boards. 
 
4. 
At the I/O board (located on far right as viewed from rear), disconnect the power supply wires 
from +6V and - terminals at J1 of I/O board. 
 
5. 
Connect the new power supply (supplied in your retrofit kit) to the I/O board.
 
6. 
Replace the fuse (F1) on I/O board with the 3 Amp fuse included in your retrofit kit.
 
7. 
Inspect the date code on existing microprocessor (U3). If it is older than 8/95, replace it with 
the new chip included with your upgrade kit. 
 
8. 
Turn DIP switch SW1-2 on I/O board Off .
 
9. 
Install your new plug-in track & hold board in the far left slot for sample points 1-4. If you 
purchased two plug-in track & hold boards, install the second board (Points 5-8) in the center 
slot. Refer to Figure 18. 
 
10. Connect output wiring to recorder or DCS from Plug-In Track & Hold Boards according to 
Figure 23.
 
11. Apply power to the sample Sequencer by plugging in your new 6 VDC power supply. 
 
12. The plug-in track & hold board will output and hold the respective 0-20 mA or 4-20 mA signal 
after the respective point has gone through one Dwell time period.
SENTRY
Equipment Corp • P. O. Box 127 • Oconomowoc, WI 53066 • 262/567-7256 • FAX: 262/567-4523
Web: www.sentry-equip.com • e-mail: [email protected]
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