What does it mean when a function is non-reentrant?

I have a BL26500 single board computer. I start my program by intializaing peripherals like the AI, AO, DIO, and high-current DO. After I call anaOutVolts, anaInVolts no longer works. Do I have to reconfigure before every call?


anaInVolts

SYNTAX: float anaInVolts(int channel, int gaincode);

DESCRIPTION: Reads the state of a single-ended analog input channel
and uses the previously set calibration constants to
convert it to volts. This function is non-reentrant.

           Note:
           -----
           If the gaincode for a given channel has changed from the
           previous cycle then the following code accesses will occur.

           1. The eeprom will be read to get the calibration constants
              for the new gain value.

           2. The DAC will be written to bias the ADC input circuit
              for proper operation (The DAC access only applies for
              the single-ended bipolar ADC operation).

PARAMETER1: ADC channel of 0 - 7, AIN00 - AIN07.

PARAMETER2: Gaincode of 0 to 7. The table below applies for Single-
Ended modes only:

				Gaincode  Macro	SE-Unipolar  SE-Bipolar
				--------  ------	-----------  ----------
	 			0 	  		GAIN_X1		20V         �10V
	 			1 	  		GAIN_X2	   10V			 �5V
	 			2 	  		GAIN_X4		 5V 		  �2.5V
	 			3 	  		GAIN_X5 	    4V		  �2.0V
	 			4 	  		GAIN_X8    2.5V		 �1.25V
	 			5 	  		GAIN_X10		 2V	  	 �1.00V
	 			6 	  		GAIN_X16	 1.25V	   	----
	 			7 	  		GAIN_X20	 1.00V	   	----

          	Note:
				------
	    		SE = Signal-Ended mode

RETURN VALUE: A voltage value corresponding to the voltage that’s on the
analog input channel, or a value of -4096 which indicates
a overflow or out of range condition.

SEE ALSO: brdInit, anaInConfig, anaIn, anaInmAmps, anaInDiff,
anaInCalib


anaOutVolts

SYNTAX: void anaOutVolts(int ch, float voltage);

DESCRIPTION: Sets the voltage of an analog output channel by using
the previously set calibration constants to calculate
the correct data values. This function is non-reentrant.

PARAMETER1: The DAC output channel (0 - 3).

PARAMETER2: The desired voltage on the output channel.

RETURN VALUE: None.

SEE ALSO: brdInit, anaOut, anaOutStrobe, anaOutConfig, anaOutCalib

Figured it out…