psiconv: 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/psiconv - from package: psiconv

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

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