ohparam: 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/ohparam - from package: openhpi32

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

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