Document Outline

• Cover Page
• Table of Contents
• Foreword
  • Purpose and Scope
  • Contents of This Manual
  • Applicable Hardware
  • General Precautions
    • Cryogen Safety
  • Safety Summary
    • Recommended Safety Equipment
    • Safety Legend
• 1 Introduction
  • 1.1 Model 187 Features
    • 1.1.1 Compensated capacitance-based level sensing
    • 1.1.2 Factory calibration
    • 1.1.3 Convenient display and direct keypad entry
    • 1.1.4 Automatic level control
    • 1.1.5 Remote computer monitoring or controlled ope...
  • Front Panel Layout
  • Rear Panel Layout
  • System Diagram
    • Figure 1-1. Model 187 instrument, control valve, a...
  • 1.5 Model 187 Specifications @ 25 ˚C
• 2 Installation
  • 2.1 Unpacking the Instrument
  • 2.2 Rack Mounting the Instrument
  • 2.3 Installing the Sensor
  • 2.4 Connecting the Model 187 to the Sensor
    • Figure 2-1. Diagram of sensor top-plate and cable ...
  • 2.5 Installing the Optional Solenoid-Operated Fill...
  • 2.6 Connecting the Instrument to Power
• 3 Operation
  • 3.1 Operational Guidelines
    • 3.1.1 Energizing the instrument
    • Figure 3-1. Default display showing level (in cm) ...
    • 3.1.2 Selecting the Appropriate Units
    • 3.1.3 Configuring the Length Settings
    • 3.1.4 Configuring the HI and LO Alarms
    • 3.1.5 Configuring the A and B Setpoints
    • 3.1.6 Selecting the Fill Mode
    • 3.1.7 Configuring the Fill Timer
  • 3.2 Sensor contamination
  • 3.3 Menu Reference
    • Figure 3-2. Default display showing level (in %) a...
    • 3.3.1 Accessing Menus
      • 3.3.1.1 Entering Numerical Values
      • 3.3.1.2 Menu Option Selection
      • 3.3.1.3 Exiting Menus
    • 3.3.2 HI Menu
    • 3.3.3 LO Menu
    • 3.3.4 A Menu
    • 3.3.5 B Menu
    • 3.3.6 RATE Menu
    • 3.3.7 LEN (Length) Menu
      • 3.3.7.1 Zero Offset
      • 3.3.7.2 Measured Span
    • 3.3.8 FILL Menu
      • 3.3.8.1 Fill Mode
      • 3.3.8.2 Fill Timeout
    • 3.3.9 MUTE Menu
    • 3.3.10 COMM Menu
      • 3.3.10.1 Display Contrast
      • 3.3.10.2 IEEE-488 Address
      • 3.3.10.3 Serial Baud Rate
      • 3.3.10.4 Serial Data Bits/Parity
      • 3.3.10.5 Serial Stop Bits
      • 3.3.10.6 Serial Handshaking
    • 3.3.11 CAL Menu
• 4 Remote Interface Reference
  • 4.1 SCPI Command Summary
  • 4.2 Programming Overview
    • 4.2.1 SCPI Language Introduction
    • 4.2.2 SCPI Status System
    • Figure 4-1. The Model 187 status system.
      • 4.2.2.1 Status Byte Registers
    • Table 4-1. Bit definitions for the Status Byte reg...
      • 4.2.2.2 Serial Polling and the Service Request (SR...
      • 4.2.2.3 Reading the Status Byte using *STB?
      • 4.2.2.4 Using the Message Available Bit(s)
    • 4.2.3 Standard Event Registers
    • Table 4-2. Bit definitions for the Standard Event ...
    • 4.2.4 Alarm Registers
    • Table 4-3. Bit definitions for the Alarm Condition...
    • 4.2.5 Command Handshaking
      • 4.2.5.1 Using the *OPC Command
      • 4.2.5.2 Using the *OPC? Query
    • 4.2.6 Remote Units
  • 4.3 RS-232/422 Configuration
    • 4.3.1 Serial Port Connector
    • 4.3.2 Termination Characters
    • 4.3.3 Flow Control Modes
  • 4.4 IEEE-488 Configuration
    • 4.4.1 Termination Characters
    • 4.4.2 Device Clear
  • 4.5 Command Reference
    • 4.5.1 System-Related Commands
    • 4.5.2 Status System Commands
    • 4.5.3 Alarm Configuration Commands and Queries
    • 4.5.4 Level and Usage Queries
    • 4.5.5 Length Configuration Commands and Queries
    • 4.5.6 Fill Mode Control and Queries
    • 4.5.7 Calibration Commands and Queries
    • 4.5.8 Remote Units Commands and Queries
  • 4.6 Error Messages
    • 4.6.1 Command Errors
    • 4.6.2 Query Errors
    • 4.6.3 Execution Errors
    • 4.6.4 Device Errors
• 5 Service
  • 5.1 Model 187 Maintenance
  • 5.2 Model 187 Troubleshooting Hints
    • 5.2.1 The Model 187 does not appear to be energize...
    • 5.2.2 The Model 187 does not remember the alarm se...
    • 5.2.3 The Model 187 displays “Over/Under Flow”.
    • 5.2.4 The Model 187 displays “Max Diel Exceeded”.
    • 5.2.5 The liquid level unexpectedly drops rapidly ...
    • 5.2.6 The liquid level unexpectedly rises rapidly ...
    • 5.2.7 The USER and FACTORY calibrations do not yie...
    • 5.2.8 The Model 187 is not responding to remote co...
  • 5.3 Additional Technical Support
  • 5.4 Return Authorization
• Appendix
  • A.1 4-20 mA Current Loop Option
  • A.2 Auxiliary Connector J8 Pinout
  • A.3 IEEE-488 Connector
    • Table A-1. IEEE-488 female connector J7 descriptio...
  • A.4 RS-232/422 Connector
    • Table A-2. PC (DB-25)-to-Model 187 connections for...
    • Table A-3. PC (DB-9)-to-Model 187 connections for ...
    • Table A-4. EIA-530 Device-to-Model 187 connections...
• Index