sst7: 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 Debian possible default full paths are:

/usr/bin/sst7 - from package: sdcc-ucsim

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

Error in other languages:
sst7: bevel nie gevind nie
sst7: comandă negăsită
sst7: comando não encontrado
sst7: commande introuvable
sst7: command not found
sst7: käsku ei ole
sst7: không tìm thấy lệnh
sst7: komanda nerasta
sst7: Kommando nicht gefunden.
sst7: kommandot finns inte
sst7: komut yok
sst7: nie znaleziono polecenia
sst7: níor aimsíodh an t-ordú
sst7: no se encontró la orden
sst7: no s'ha trobat l'ordre
sst7: opdracht niet gevonden
sst7: parancs nem található
sst7: perintah tidak ditemukan
sst7: príkaz nenájdený
sst7: příkaz nenalezen
sst7: команда не найдена
sst7: командата не е открита
sst7: 命令找不到
sst7: コマンドが見つかりません