MO31 will be rejected when Closing Condition Order Flag (exch_order_type_n) or Closing Condition Session Specification (ext_t_state_c) is sent with no value.
Please refer below for the error code when MO31 is rejected:

 

[Premise]
If NULL = 0x00, value “0” and NULL will be considered the same value, therefore if NULL is set, NULL will be considered as “0”.

 

[Error Code]
Case 1:
“0” (=NULL) is set to exch_order_type_n (Closing Condition Order Flag) and [1], [2], [3], [4], or [5] is set to ext_t_state_c (Closing Condition Session Specification)
>Order will be rejected with “-420453：State Type valid only for State Type Orders”.

 

Case 2:
512 (=closing condition) is set to exch_order_type_n (Closing Condition Order Flag) and “0” (=NULL) is set to ext_t_state_c (Closing Condition Session Specification).
>Order will be rejected with “-420451：State Type Order must specify state type”.

For closing condition orders, please avoid setting values other than [1], [2], [3], [4], or [5] to ext_t_state_c (Closing Condition Session Specification).

 

For details, please refer to “Orders triggered in Closing auction” under “4.6.3.1 Considerations for Normal Orders” of “J-GATE3.0_Connectivity_Manual_Commonalities_part”.