plugctl: 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/plugctl - from package: libiec61883-utils

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

On Debian possible default full paths are:

/usr/bin/plugctl - from package: libiec61883-dev

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

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