i_EPIC FAQ

Table of Contents

  1. How do I diagnose a failed EPIC run?
  2. How do I run EPIC manually?
  3. Error messages appear, related to data access.
  4. What is LUN (and how is USDA Crop ID used)?
  5. What tillage codes does i_EPIC use (and why)?
  6. How are PRNT file codes entered?

How do I diagnose a failed EPIC run?

a - Examine the console output, either by watching the run in a visible console window, or by running epic manually (see item 2 below).  If EPIC crashes while reading in a specific input file it may give some hint at least of what file was being read when the error occured.  Using a version of EPIC.exe compiled with debug options should give you a line number in the epic Fortran code which may help.

b - Examine the output file, ie.out (for newer versions of EPIC this file is called EPIC0001.out).  If EPIC crashes after it has begun writing the output file, you can compare an incomplete output file to a successful run to see which section of the program failed.

c - Examine the input files.  Open a command prompt and change directory to where EPIC runs.  I_EPIC writes the following files to an EPIC 5300 directory just before a run:


ie.dat
ie.epc
ie.sum
ieCrop.dat
ieFert.dat
ieParm.dat
iePest.dat
iePrnt.dat
ieTill.dat
and the following to an EPIC8120 directory:

epicfile.dat
epicrun.dat
ie.dat
ieCrop.dat
ieFert.dat
ieOpList.dat
ieOps.dat
ieParm.dat
iePest.dat
iePrnt.dat
ieSlList.dat
ieSoil.dat
ieTill.dat
Examine each one using the EPIC UTIL program and/or printed EPIC documentation to check for valid values.  Use defaults where possible.

d - The Last Stand of Desperation.  Rename and replace each EPIC input file with a known, successfully run file (like those provided as samples with EPIC) and re-run by hand as described in item 2 below.  If replacing a particular file causes EPIC to complete the run, begin replacing single records or lines of the invalid version with those from the working one using a text editor like Notepad.  Repeat until (hopefully, eventually) a single number value is implicated.

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2. How do I run EPIC manually? Open a command prompt (in the Start Menu as "MS-DOS Prompt" in Windows 95 or 98, "Command Prompt" in Windows NT).  Change directory to the installed EPIC directory (displayed within I_EPIC under "File" | "Configuration"), something like:

cd c:\Program Files\i_EPIC\EPIC5300
Enter the following command:
ewq ie (for EPIC 5300)
epic8120 (for EPIC 8120)
epic0250 (for EPIC 0250)
epic1015 (for EPIC 1015)
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3.Error messages appear, related to data access.

Note: Windows 2000 and/or Office 2000 use a changed file format for Access databases.  I_EPIC has been updated for compatibility with the newer components.

The Jet VBA file (VBAJET.dll for 16-bit version, or VBAJET32.dll for 32-bit versions) failed to initialize when called. Try reinstalling the application that returned the error.
or

Command Failed (when opening a .MDB file)

These messages indicates an incorrectly installed or mismatched set of the DLL files necessary to provide DAO (database) access.

You'll need to

Download and install Microsoft's "MDAC 2.5" components from http://www.microsoft.com/data/download.htm

Download and install Jet 4.0 components from http://support.microsoft.com/support/kb/articles/Q239/1/14.asp

You may need to make copy of "\Windows\System\dao360.dll" and put it in the directory "\Program Files\Common Files\Microsoft Shared\DAO".

You may need to "register" the DAO360.dll file by running this command: "c:\windows\system\regsvr32 dao360.dll".

Older Windows 95 systems may need to download and install DCOM95.

Some useful terms when installing these things:


ODBC - Open DataBase Connectivity.  This is a set of libraries that allows a program to access various database formats in a consistent way.  I_EPIC no longer uses this.
DAO - Data Access Objects.  This is a Microsoft-specific set of libraries for accessing only Microsoft Access database file format.  I_EPIC now uses DAO 3.6.
Jet - A name for the specific code engine that reads and writes an Access database via DAO.
OLE DB - Newer Microsoft database API. i_EPIC is being gradually switched over from DAO to this system because it eliminates some of the above installation problems. Text fields in all tables written by OLE DB must be designated "Allow Zero Length = YES"

4. What is LUN (and how is USDA Crop ID used)?  See EPIC Crop Codes

5. What tillage codes does i_EPIC use (and why)?  See Tillage Definitions

6. How are PRNT file codes entered?  Select "File" | "Set Stored Output Variables".  The choices given are read from the file "output variables.csv".  See EPIC Output Codes

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