sip2ncid: 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/sbin/sip2ncid - from package: ncid

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

Error in other languages:
sip2ncid: bevel nie gevind nie
sip2ncid: comandă negăsită
sip2ncid: comando não encontrado
sip2ncid: commande introuvable
sip2ncid: command not found
sip2ncid: käsku ei ole
sip2ncid: không tìm thấy lệnh
sip2ncid: komanda nerasta
sip2ncid: Kommando nicht gefunden.
sip2ncid: kommandot finns inte
sip2ncid: komut yok
sip2ncid: nie znaleziono polecenia
sip2ncid: níor aimsíodh an t-ordú
sip2ncid: no se encontró la orden
sip2ncid: no s'ha trobat l'ordre
sip2ncid: opdracht niet gevonden
sip2ncid: parancs nem található
sip2ncid: perintah tidak ditemukan
sip2ncid: príkaz nenájdený
sip2ncid: příkaz nenalezen
sip2ncid: команда не найдена
sip2ncid: командата не е открита
sip2ncid: 命令找不到
sip2ncid: コマンドが見つかりません