Sigma C4 manual P1f, Fahrenheit Operation

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3.4 Fahrenheit Operation

The C4 can use either Celsius or Fahrenheit temperature scales. Celsius is the default mode. When the controller is operating in Celsius mode it’s behavior is identical to the model CC-3 controller. When the controller is operating in Fahrenheit mode, both the displays and the bus communications are different. These differences are intentional and designed to prevent errors that might arise from a user using setpoints in one scale while the controller is operating in the other scale. Note, however, that there is no difference in the Program mode programming operation of the C4 when operating in either Fahrenheit or Celsius mode. It is incumbent upon the user to notice the differences in the temperature displays and program accordingly.

To change the temperature scale, use SETUP mode (See Section 8) to access setup parameter F16. Select either of these field values:

0Celsius

1Fahrenheit

When in Fahrenheit mode, temperature displays have an “F” following the probe identifier on the left side of the display. Example:

p1f 102.4

Likewise, temperature inquires over the bus (PT command - See Section 7.5.7) will return a string with an “F” as the third byte in the string. The string will therefore be 1 byte longer than the string returned in Celsius mode. This difference was intentional as it requires a modification of the parsing routine that will assure that Celsius and Fahrenheit data are recognized properly. Thus, if the current probe 1 temperature is 86.7/F, the result of a Fahrenheit mode get temperature query for probe 1 (query command = PT1) would be

T1F 86.7<CR><LF>

If the temperature at probe 1 was 55.4/C, the same command in Celsius mode would return

T1 55.4<CR><LF>

During Remote mode operation, the C4 may be queried to determine the current temperature scale by using the QS, Query Setpoint, command. See Section 7.4.4.

C4 Manual Rev 7.5.2

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Contents Sigma Systems Programmable Temperature Controller / InterfaceC4 Manual Rev Table of Contents Intelligent 2 Probe Control C4 Manual Rev C4 Manual Rev C4 Manual Rev C4 Manual Rev Models C4 & CC-3.5Explained IntroductionGeneral Description Release 7.5.2 Firmware Custom Features / Interchangeability WarningC4 vs. CC-3 Differences What’s New Firmware Uploads Forced Start from Prom Firmware Internal Error Shutdown Conditions Intelligent 2 Probe Control Probe Averaging Program Mode Step Insert & Delete RSA Remote Mode Setup Parameter Commands Front Panel Physical DescriptionMode Switch Clear Prog J1 TOP Rear Panel ConnectionsC3-5 Rel General Operation & Error Conditions200 100c 392 148f Startup DisplaysUpdating Firmware Upgrading Firmware by Prom Replacement Making the physical connection for upload Rs load Restoring Setup Parameters to Default ValuesSu res Ee busy and then su doneC4 Manual Rev Fahrenheit Operation P1fProbe Out of Range Shutdown System Operating Temperature RangeP1 lo P1 hi P1 err P1 -err All res Internal Error Shutdown ConditionsRes err Software Probe Correction Calibration Su errStatus and Error Reporting Fail-safe System C4 Manual Rev Intelligent 2 Probe Control How Intelligent 2 Probe Control functions Preparing for Intelligent 2 Probe Control Using Intelligent 2 Probe Control Displaying Temperature Local Mode Basic OperationDisplaying and Changing the Setpoint S1 102.6 s1fS1 nsp S1f nsp Controlling to a Setpoint Sor -sorSp err C4 Manual Rev Description of a Program Step Program Mode06.0 00.1 Substep Step Data 00.0Ramp time 00.2Maximizing Ramp Speed & Other Ramp Considerations Displaying Program Steps not during execution Clearing Program Memory Reinitializing program stepsPress CLEAR/ENTRY Entering or Changing a Program StepInsert Program Step Running Executing a Program Delete Program stepPress CLEAR/ENTRY Press CLEAR/ENTRY again Program Run Time Information/Considerations 005 sor Sor 007 nop2Loop Special Commands External Compressor On Common Programming Issues C4 Manual Rev IEEE-488 Interface Remote ModeEIA-232 Interface System Information Queries Command Summary by functional groupSystem Information Queries For Celsius mode For parameters numbered 0 through C4 Manual Rev Operation Information Queries & Commands REerror byteCRLF C4 Manual Rev Qccrlf PTnCRLF Setup Parameter Commands SC1 0 2.3 100 WP 6 5 5CRLF Upcrlf System Operation Commands Celsius mode Will hold the current setpoint for 1 hour and 20 minutes U1c 65.0 u1f IEEE-488 Gpib Error and Status Reporting OverviewTemperature in 20 minutes C4 Manual Rev Error/Status String Bit Definitions C4 Manual Rev Setup Mode PID controller, Integral term Adjustment not Displaying the Field Values Auto-start Mode Setup field Changing the Value of a Setup FieldTwo Probe Mode Setup field Temperature Control Terms PID Setup fields 0, 10, 11 Blower Shut-off Mode Setup fieldEntering probe correction setup data C4 Manual Rev C4 Manual Rev Programming Examples & Notes Appendix00.2 00.000.3 00.4Using shortcuts to shorten program entry time DISP/CNTLSTART/STOP 9900CLEAR/ENTRY 6 Enter 04.2 04.004.3 04.407.2 07.007.3 07.4C4 Manual Rev Sigma Systems C4 Programming Worksheet Sample Command Structure for IEEE-488 Gpib Operation Disp A$ Installation and Use of TTL Outputs and Input 101 Field Calibration of Model C4 Controller102 103 TroubleshootingNoise Immunity 105 Firmware Upload Problems 107 Temperature Control PID Tuning & Problems108 109 110 111 Technical Support, Repairs & Returns U1f 102.7113 Index114 115 GpibIEEE488 Gpib 117 118 119 SRQ120