tcat: 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/tcat - from package: gsm-tools

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

On Debian possible default full paths are:

/usr/bin/tcat - from package: libgsm-tools

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

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