M1RB wiring harness length

[tomtnt]

Does anyone know how long the wiring harness length can be extended? I'd like to hook up the M1RB to my panel to convert the 8 voltage outputs to relays for use with sprinklers. I'd like to have the M1RB in the garage. I currently have an additional M1OVR+M1RB in the garage but have used up all those outputs. I'd rather not have to buy another M1OV/M1OVR if I can use the built in outputs with the M1RB