Kiethly 2400 Error 113 "Undefined Header"

Question

Hello,
   I am currently using a Keithley 2400 both as a current source and as a measuring device.  The program I am running is based on the Keithly 24xx drivers  (http://sine.ni.com/apps/utf8/niid_web_display.dow​nload_page?p_id_guid=25B255F3AA83660EE0440003BA7CC​D71). 
The program works perfectly for about 30 seconds of data collection, then shows Error 113 Undefined Header, then begins to work again after a brief interruption.  The error will then appear randomly after that.  Does anyone know what is causing this error and how to stop it?  My code can be found attached to the message
I ran NI SPY and the following was highlighted red: >
697.  viWaitOnEvent (GPIB0::16::INSTR (0x02D08828), IO_COMPLETION, 0, 0, 0x00000000)
> Process ID: 0x00000874         Thread ID: 0x00000D10
> Start Time: 15:31:10.343       Call Duration 00:00:00.000
> Status: 0xBFFF0015 (VI_ERROR_TMO)
from 697 to 708
The lines before it were:
695.  VISA Write ("GPIB0::16::INSTR", ":ARM:COUN 1;:TRIG:COU...")
Process ID: 0x00000874         Thread ID: 0x00000FA4
Start Time: 15:31:10.328       Call Duration 00:00:00.000
Status: 0 (VI_SUCCESS)
 696.  VISA Write ("GPIB0::16::INSTR", "ARMOUR IMM;:ARM:TIM...")
Process ID: 0x00000874         Thread ID: 0x00000FA4
Start Time: 15:31:10.328       Call Duration 00:00:00.015
Status: 0 (VI_SUCCESS)
the lines after it were:
 709.  viWaitOnEvent (GPIB0::16::INSTR (0x02D08828), IO_COMPLETION, 0, IO_COMPLETION, 0x02DA2878)
Process ID: 0x00000874         Thread ID: 0x00000D10
Start Time: 15:31:10.343       Call Duration 00:00:00.000
Status: 0 (VI_SUCCESS)
710.  Completing viWriteAsync (GPIB0::16::INSTR (0x02D08828), 0x04045CD1, "ARMOUR IMM;:ARM:TIM...", 65)
Process ID: 0x00000874         Thread ID: 0x00000D10
Start Time: 15:31:10.343       Call Duration 00:00:00.000
Status: 0 (VI_SUCCESS)
Attachments:
Source_Current_Meas_Volt_Single_Read.vi ‏68 KB

Answer 1

The error occurs when the VI code is at the "read single" point of the VI. When I watch the sub VI's, the progression is that under the read single VI, it occurs at the read multiple points VI, and under that VI with error 1073807339 at the Fetch Measurements VI, and under that VI it occurs, with the same error code 1073807339 at the VISA Read and the Property Node.  I have attached the spy file with just my program open, and with the Fetch program open. 
Attachments:
Capture.spy ‏265 KB
capture with fetch subvi runnning.spy ‏265 KB