Can F5 solve SCADA issues?

F5 ASM is Web Application Firewall protecting as the name implies Web applications using HTTP protocol. MODBUS/TCP is a serial protocol and is not HTTP. It is however possible to provide a level of protection using F5 LTM as a reverse proxy and iRules, Marc Chisinevski from F5 last year demonstrated some use cases that he implemented using iRules:

Protocol validation; Modbus TCP packets that are of wrong size or length
Potential DoS attacks - Traffic from a server to many slaves
Traffic on TCP port 502 that is not Modbus
Function and configuration scans
Function codes putting slave devices into listen-only mode
Function codes that modify diagnostic information
Function codes that cause the unit to shutdown, requiring someone physically at the site to restart the device
Exception PDUs

Ref: https://www.linkedin.com/pulse/security-use-cases-modbustcp-marc-chisinevski-cissp/