fpga_load: 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/fpga_load - from package: dahdi-tools

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

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