Software Serial Input not reading/encoding properly

I have been working on a project that needs to get data from two different serial ports. I am using one device on the native serial pins and I am not having any issues with that device. To be able to get data from the second serial device I am trying to use a software serial setup. (I have tried both the softwareserial and the AltSoftSerial libraries with the same results). I can tell that the data is being received but the serial data is being "scrambled" for lack of a better word. What I am seeing resembles what I would expect to see in a telnet program if baud rates were not the same. I have verified baud rates on all devices and they are correct.

For example: Data sent to Arduino: "Hello World from TXTlandia..."
Data "received" by Arduino (based on serial.print): ú‹…e'7¿3e!%¿WOW'=#7-=£££åë

The result is constant... ie send the same string and get the same output every time. What simple step am I missing or mis-understanding that I can't get the Arduino to properly read the serial data?

Below is my current code:

#include <AltSoftSerial.h>

/*
This project will allow a service technician to field test
print signals going out to SATO printers.
*/

#define DataStatus 13

//Software Serial Port: RX = 8, TX = 9)
//const byte rx = 8; //Brown
//const byte tx = 9; //Blue
AltSoftSerial pntData;  //(rx, tx)

String DataIn;
const byte numChars = 32;
char receivedChars[numChars];
boolean newData = false;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(19200);
  while (!Serial) {}
  pinMode(DataStatus, OUTPUT);
  pntData.begin(19200);
   
}

void loop() {
  // put your main code here, to run repeatedly:
    
  while (pntData.available()==0){
  Serial.println("No Data Availible...");
  digitalWrite(DataStatus, HIGH);
  delay(250);
  digitalWrite(DataStatus, LOW);
  delay(250);
  }

  recvData();
  
}

void recvData() {
 
  static byte ndx = 0;
  char endMarker = '\n';
  char rc;
  
  while (pntData.available() > 0 && newData == false) {
        rc = pntData.read();

        if (rc != endMarker) {
            receivedChars[ndx] = rc;
            ndx++;
            if (ndx >= numChars) {
                ndx = numChars - 1;
            }
        }
        else {
            receivedChars[ndx] = '\0'; // terminate the string
            ndx = 0;
            newData = true;
        }
    }
    
    DataIn = receivedChars;
        
    showNewData();
  
}

void showNewData() {
    if (newData == true) {
        Serial.print("Data Received: ");
        Serial.println(DataIn);
        newData = false;
    }
}

** DataIn = receivedChars;**

nope

Not sure what your answer "nope" is actually referring to...

whether I directly print it using serial.Println(receivedChars) or first set the variable DataIn using the command DataIn = receivedChars and then printing it using serial.Println(DataIn) the result is identical...

Could you be more specific with your response?

Looking at the bit patterns it appears you have the polarity of the signal reversed. Answering your question with all the data given is like Piece of cake, simply tell me what color blouse my Manager's wife had on last October and you will then have your answer. Maybe it would be better to post a schematic and parts of the code. It is best to do a real schematic, not one of the fuzzy things.