Now you have rephrased your question and I think Daniel's answer was given according to the original form of your question.
Or do we need to assign the VFD signals to a non-Hart card.??
The simple answer is no. You don't need additional modules.
You can assign the VFD signals to the HART module.
In the above mentioned manual you can read,
● 8 outputs (current)
– 15 bits (0..20mA)
– 15 bits (+ sign) (4..20mA)
● Output type selectable per channel:
– Current output with HART
– Current without HART
– Channel deactivated
● Selection of any output range per channel
– 0...20 mA (with HART)
– 4...20 mA (with HART)