fvnet: command not found

Have You tried accessing the binary with the full path?

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/fvnet - from package: fawkes-firevision-tools

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