Large current affect DCM???

Hello all,
My block plant is controlled by an SLC5/03 which contains the program for all machines involved in the process. This chassis contains a 1747SN. Parameters on all machines are entered via a panelview B6C2.
The mixing section of the plant is some distance from the main control panel and all I/O's are wired to an SLC5/02 with a DCM. There is also an SMC Flex 150 in close proximity (about 3 feet away) to the 5/02 with a 150HP 415V motor some 20 feet further away.
The cuber is also quite a distance (30 metres) from the main control panel. It's I/O's are wired to a 5/03 also with a DCM. The communication loop is terminated at this DCM with the appropriate thingo( I can't remember what they're called). The cuber program file(s) utilises inputs to move increasing numbers to an integer file (eg when N7:3 equals 4 elevator up) until the sequence is finished, at which point a zero is moved to that file.
Everything works perfectly except, on random occasions, when the mixer motor is winding up to speed, the cuber stops whatever motion it is doing. I go online to the main 5/03 to find random numbers (always different) in whatever integer file was being used by the cuber at that time.
Any suggestions as to why this is happening would be appreciated.
Many thanks

I would suspect you are getting noise from the VFD.

Thanks Ken for your reply. If noise is the problem, can you suggest a solution short of physically moving either the VFD or 5/02 as this would be VERY difficult.
Thanks, Clayton

Exactly how are things currently wired?

Sorry about the delay in replying- roadtrain took out powerlines last night. Cuber inputs are via 3 IV16 cards in slots 2,3 & 4(not used). Outputs are via 2 OA16 cards in slots 5 & 6. DCM is configured for full rack and is in slot 1. SLC 5/03 is the CPU.
Mixer inputs are via 2 IB16 cards in slots 5 & 6. Outputs are via 2 OW16 cards in slots 2 & 3, 1 OA16 card in slot 4 and 3 OB16 cards in slots 7,8 & 9(not used at this time). DCM is configured for full rack and is in slot 1. SLC 5/02 is the CPU.
1747SN scanner resides in slot 5 of the main controller(5/03) along with I/O's for the block machine which have been unaffected by this problem.
The SMC Flex has no communication with any SLC.
Program for cuber 5/03 is;
Rung 0001 MOV I:1.2 O:5.0
Rung 0002 MOV I:1.3 O:6.0
Rung 0003 MOV I:2.0 O:1.3
Rung 0004 MOV I:3.0 O:1.4
Program for mixer 5/02 is;
Rung 0001 MOV I:1.2 O:2.0
Rung 0002 MOV I:1.3 O:3.0
Rung 0003 MOV I:1.4 O:4.0
Rung 0004 MOV I:5.0 O:1.5
Rung 0005 MOV I:6.0 O:1.6
I can provide the main program, however, it is quite large. Can this be done with an attachment in this forum?
Thanks for all help, Clayton