Use the INACTTIME statement to specify the amount of time the FTP client waits for an expected response from the server, on either the control or the data connection, before closing the session. Data transfer times that exceed this value does not cause session termination unless the time between data packet arrivals exceeds this value.
.-INACTTIME 120------. >>-+--------------------+-------------------------------------->< '-INACTTIME--seconds-'
INACTTIME 160 ; wait 160 seconds
None
See the FTP command and FTP environment information in z/OS Communications Server: IP User's Guide and Commands.