Problem executing process chain using planning function

Hi everybody,

I created a simple custom Function module to execute process chain using planning function.

The Function Module is as follows

FUNCTION Z_FM_PCHAIN.

*"----

""Local Interface:

*" IMPORTING

*" VALUE(I_CHAIN) TYPE RSPC_CHAIN OPTIONAL

*" VALUE(I_T_VARIABLES) TYPE RSPC_T_VARIABLES OPTIONAL

*" VALUE(I_SYNCHRONOUS) TYPE RSPC_SYNCHRONOUS OPTIONAL

*" VALUE(I_SIMULATE) TYPE RSPC_SIMULATION OPTIONAL

*" VALUE(I_NOPLAN) TYPE RS_BOOL OPTIONAL

*" EXPORTING

*" VALUE(E_LOGID) TYPE RSPC_LOGID

*"----

DATA: l_guid TYPE sysuuid_25,

l_local_log TYPE rspc_logid,

l_variant TYPE rspc_chain,

l_instance TYPE rspc_instance,

l_state TYPE rspc_state.

l_variant = I_CHAIN.

CALL FUNCTION 'RSPC_CHAIN_START'

EXPORTING

i_chain = l_variant

IMPORTING

e_logid = e_logid.

ENDFUNCTION.

I have used the above FM (Z_FM_PCHAIN) in FM initialization and a dummy FM in Function module.

I have entered the parameter exit function values as i_chain(parameter) and rspc_chain (dataelement) hoping that this parameter value will be passed into the above FM: z_fm_pchain and the process chain gets executed. But I am getting the following dump.

********************************************************************

"when calling the function module "Z_FM_PCHAIN", one of the parameters needed according to the interface description was not specified. This parameter was "I_CHAIN" "

********************************************************************

Now, when i am testing the FM : Z_FM_PCHAIN independently it is working fine but when i am trying to pass the parameter into the FM i am getting the above dump.

Plz let me know how to overcome the above problem.

Thank you guys in advance