Related Manuals for Keithley 7999-2
Summary of Contents for Keithley 7999-2
- Page 1 Model 7999-2 Multiplexer Card Instruction Manual Contains Operating and Servicing Information...
- Page 2 WARRANTY Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of shipment. Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batter- ies, diskettes, and documentation.
- Page 3 Model 7999-2 Three-Pole Multiplexer Card Instruction Manual ©1999, Keithley Instruments, Inc. All rights reserved. Cleveland, Ohio, U.S.A. First Printing, September 1999 Document Number: 7999-2-901-01 Rev. A...
- Page 4 Revision A (Document Number 7999-2-901-01)............ September 1999 All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc. Other brand names are trademarks or registered trademarks of their respective holders.
- Page 5 As described in the International Electrotechnical Commission (IEC) Standard IEC 664, digital multimeter measuring circuits (e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are Installation Category II. All other instruments’ signal terminals are Installation Category I and must not be connected to mains.
- Page 6 To maintain protection from electric shock and fire, replacement components in mains circuits, including the power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals, may be used if the rating and type are the same. Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component.
- Page 7 7999-2 Three-Pole Multiplexer Card RELAY SWITCH CONFIGURATION: GENERAL 1 bank of 3:1 mux 3-pole switching. 1 bank of 4:1 mux 3-pole switching. ENVIRONMENT: Operating: 0° to 50°C, up to 35°C <80% RH. CONTACT CONFIGURATION: 3-pole Form A. Storage: –25° to 65°C.
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Page 8: Table Of Contents
Table of Contents General Information Introduction ................1-2 Feature overview ................ 1-2 Warranty information ..............1-2 Manual addenda ................. 1-2 Safety symbols and terms ............1-3 Specifications ................1-3 Unpacking and Inspection ............1-3 Inspection for damage ............1-3 Handling precautions ............1-3 Shipment contents ............... - Page 9 Service Information Introduction ................4-2 Handling and cleaning precautions ..........4-2 Handling precautions ............4-2 Card cleaning ............... 4-2 Performance verification ............. 4-3 Environmental conditions ............ 4-3 Recommended equipment ........... 4-3 Multiplexer card connections ..........4-4 Channel resistance tests ............4-4 Contact potential tests ............
- Page 10 List of Illustrations Connections Figure 2-1 Card configuration ..............2-3 Figure 2-2 Simplified schematic .............. 2-4 Figure 2-3 Input/output connector terminal designations ......2-5 Figure 2-4 AUDIO IN AUDIO OUT connector terminals ....... 2-6 Figure 2-5 CONTROL/MEASURE/POWER connector terminals ..2-7 Operating Considerations Figure 3-1 Path isolation resistance ............
- Page 11 List of Tables Connections Table 2-1 Input/output connector terminals ........... 2-5 Table 2-2 AUDIO IN AUDIO OUT connector terminals ....... 2-6 Table 2-3 CONTROL/MEASURE/POWER connector terminals ..2-7 Service Information Table 4-1 Recommended verification equipment ........4-3 Replaceable Parts Table 5-1 Parts list ..................
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Page 12: General Information
General Information... -
Page 13: Feature Overview
Warranty information is located at the front of this instruction manual. Should your Model 7999-2 require warranty service, contact a Keithley representative or an authorized repair facil- ity in your area for further information. When returning the card for repair, be sure to fill out and include the service form at the back of this manual to provide the repair facility with the necessary information. -
Page 14: Safety Symbols And Terms
Unpacking and Inspection Inspection for damage The Model 7999-2 is packaged in a re-sealable, anti-static bag to protect it from damage due to static discharge and from contamination that could degrade its performance. Before remov- ing the card from the bag, observe the precautions on handling discussed below. -
Page 15: Shipment Contents
Keithley part number 7999-2-901-00. The manual package includes an instruction manual and any pertinent addenda. Repacking for shipment Should it become necessary to return the Model 7999-2 for repair, carefully pack the unit in its original packing carton or the equivalent, and perform the following: •... -
Page 16: Connections
Connections... -
Page 17: Introduction
Connections Introduction This section contains information about overall card configuration and connections and is organized as follows: • Handling precautions • Card configuration • Connections WARNING The procedures in this section are intended only for qualified service per- sonnel. Do not perform these procedures unless you are qualified to do so. Failure to recognize and observe normal safety precautions could result in personal injury or death. -
Page 18: Card Configuration
Connections Card configuration Card layout Figure 2-1 shows the general layout of the Model 7999-2. Connectors include: • Input/output connectors — A 3-pin Lemo connector is provided for each of the seven multiplexer input/output channels (XEAR, BUZZ_MIC, EAR_MIC, LEVELING_MIC, XMIC, LSP, SPECIAL_AUDIO). -
Page 19: Simplified Schematic
Connections Simplified schematic Figure 2-2 shows a simplified schematic diagram of the Model 7999-2. The card is arranged into two multiplexer banks: • One bank of 3:1 3-pole switching • One bank of 4:1 switching NOTE Single pole switching is shown in Figure 2-2 for simplicity. H, L, and G indicates separate HI, LOW, and GND signal switching. -
Page 20: Card Connections
Connections Card connections Input/output connectors Figure 2-3 provides the terminal configuration for the input/output connectors (XEAR, BUZZ_MIC, EAR_MIC, LEVELING_MIC, XMIC, LSP, SPECIAL_AUDIO), while Table 2-1 summarizes signals. Table 2-1 Input/output connector terminals Connector pin Signal Figure 2-3 Input/output connector terminal designations... -
Page 21: Audio In And Audio Out Connector
Connections AUDIO IN and AUDIO OUT connector Figure 2-4 shows the terminal configuration for the AUDIO IN AUDIO OUT connector, and Table 2-2 summarizes signals. Table 2-2 AUDIO IN AUDIO OUT connector terminals Connector pin Signal AUDIO OUT HI AUDIO OUT LO AUDIO OUT GND AUDIO IN HI AUDIO IN LO... -
Page 22: Control/Measure/Power Connector
Connections CONTROL/MEASURE/POWER connector Figure 2-5 shows the terminal configuration for the CONTROL/MEASURE/POWER con- nector, and Table 2-3 summarizes terminal designations along with switched signals. Table 2-3 CONTROL/MEASURE/POWER connector terminals Terminal Description Switched signal(s) DVM+ CONTROL 6 EAR_MIC DVM- CONTROL 7 MEASVOLT, LEVELING_MIC +24V CONTROL 8... -
Page 23: Operating Considerations
Operating Considerations... -
Page 24: Maximum Signal Considerations
See Section 2 for complete connection information. Table 2-3 in Section 2 lists switched signals. Switching considerations Signals switched by the Model 7999-2 may be subject to various effects that can seriously affect their integrity. The following paragraphs discuss these effects and ways to minimize them. -
Page 25: Path Isolation
Operating Considerations problems, never touch the connector insulating material. In addition, the multiplexer card should be used only in clean, dry environments to avoid contamination. If the connector insulators should become contaminated, either by inadvertent touching, or from air-borne deposits, they can be cleaned with a cotton swab dipped in clean methanol. After thoroughly cleaning, they should be allowed to dry for several hours in a low-humidity environment before use, or they can be dried more quickly using dry nitrogen. -
Page 26: Insertion Loss
(connectors, PC board traces, and relays). The Model 7999-2 has an insertion loss figure of <0.1dB at audio frequencies up to 20kHz (50 Ω source and load impedances), which should not be a consideration in most cases. -
Page 27: Ground Loops
Operating Considerations Ground loops When two or more devices are connected together, care must be taken to avoid unwanted signals caused by ground loops. Ground loops usually occur when devices are connected with more than one signal return path such as power line ground. As shown in Figure 3-3, the result- ing ground loop causes current to flow through LO signal leads and then back through power line ground. -
Page 28: Service Information
Service Information... -
Page 29: Introduction
Handling and cleaning precautions Because of the high-impedance areas on the Model 7999-2, care should be taken when han- dling or servicing the card to prevent possible contamination. The following precautions should be observed when servicing the card. -
Page 30: Performance Verification
Service Information Performance verification The following paragraphs discuss performance verification procedures for the Model 7999-2, including channel resistance, contact potential, and channel-to-channel and common- mode isolation. CAUTION Contamination will degrade the performance of the card. To avoid contamination, always grasp the card by the cover; do not touch the connectors. -
Page 31: Multiplexer Card Connections
EX TRIG TRIG STORE FILTER RECALL 3A 250V AMPS POWER RANGE SAVE SETUP CONFIG HALT GPIB RS232 TEST OPEN CLOSE STEP SCAN DIGITS RATE EXIT ENTER Model 7999-2 Relay Model 2010 DMM Under Test. See Section 2 for Detailed Connections. -
Page 32: Contact Potential Tests
SETUP RS232 TEST GPIB Connect to and CAT I STEP SCAN SAVE RESTR DIGITS RATE EXIT ENTER 350V PEAK ANY TERMINAL TO CHASSIS use Channel 1 Model 2182 Nonovoltmeter Model 7999-2 Relay Under Test. See Section 2 for Detailed Connections. -
Page 33: Channel-To-Channel Isolation Tests
Select the Model 6517A ohms function and 2G Ω range, and enable zero check. Make sure the voltage source is in standby. Connect the electrometer to the two Model 7999-2 channels being tested, as shown in Figure 4-3. Note that electrometer INPUT HI is connected to one channel, while VOLTAGE SOURCE HI is connected to the other channel. -
Page 34: Common-Mode Isolation Tests
Select the Model 6517A ohms function and 2G Ω range, and enable zero check. Make sure the voltage source is in standby. Connect the electrometer to the Model 7999-2 channel being tested, as shown in Figure 4-4. Note that electrometer INPUT HI is connected to the tested channel, while VOLT- AGE SOURCE HI is connected to system ground. -
Page 35: Replacing Components
After cleaning, allow the card to dry in a 50˚C low-humidity environment for several hours before use. Disassembly Perform the following steps to disassemble the Model 7999-2 to gain access to parts on the circuit board: Remove the six screws that hold the case together. -
Page 36: Replaceable Parts
Replaceable Parts... -
Page 37: Introduction
Component designation (if applicable) • Keithley part number Factory service If the card is to be returned to Keithley Instruments for repair, perform the following: • Call the Repair Department at 1-800-552-1115 for a Return Material Authorization (RMA) number. •... - Page 38 Replaceable Parts Component layout and schematic diagram The following component layout and schematic diagram drawings are provided on the fol- lowing pages: • Component layout drawing: 7999-2-100 • Schematic diagram: 7999-2-106 Table 5-1 Parts list Circuit designation Description Keithley part no.
- Page 43 Index Keeping connectors clean 3-2 AUDIO IN and AUDIO OUT connector 2-6 Manual addenda 1-2 Maximum signal considerations 3-2 Multiplexer card connections 4-4 Card cleaning 4-2 Card configuration 2-3 Card connections 2-5 Operating considerations 3-1 Card layout 2-3 Ordering information 5-2 Channel resistance tests 4-4 Channel-to-channel isolation tests 4-6 Common-mode isolation tests 4-7...
- Page 44 Keithley Instruments, Inc. 28775 Aurora Road Cleveland, Ohio 44139 Printed in the U.S.A.
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