ascii-xfr: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/ascii-xfr - from package: minicom

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/ascii-xfr - from package: minicom

You may install the required package with command apt-get install {package}

Error in other languages:
ascii-xfr: bevel nie gevind nie
ascii-xfr: comandă negăsită
ascii-xfr: comando não encontrado
ascii-xfr: commande introuvable
ascii-xfr: command not found
ascii-xfr: käsku ei ole
ascii-xfr: không tìm thấy lệnh
ascii-xfr: komanda nerasta
ascii-xfr: Kommando nicht gefunden.
ascii-xfr: kommandot finns inte
ascii-xfr: komut yok
ascii-xfr: nie znaleziono polecenia
ascii-xfr: níor aimsíodh an t-ordú
ascii-xfr: no se encontró la orden
ascii-xfr: no s'ha trobat l'ordre
ascii-xfr: opdracht niet gevonden
ascii-xfr: parancs nem található
ascii-xfr: perintah tidak ditemukan
ascii-xfr: príkaz nenájdený
ascii-xfr: příkaz nenalezen
ascii-xfr: команда не найдена
ascii-xfr: командата не е открита
ascii-xfr: 命令找不到
ascii-xfr: コマンドが見つかりません