how to read 2 VISA Resource Name on same vi

[rhiesnand]

hi all, i made program for read counter value via modbus, but i have limit slave only 31 slave and my program need more than 31 slave, so i made 2 VISA Resource Name on same vi (1 vi). but it only can read 1 VISA Resource Name, what the problem ? i check on device manager and change port number still didnt work, this is my simple program, whats wrong on my method ? please help. thanks...