Elk's delay between events

I've put together a simple "system" to scare the cat off the countertop:
 
An old X10 motion sensor and an equally old (5 yeras ?) Intermatic zwave appliance module plus a rule.  Interestingly, both work quite well.
 
However, there's a  consistent 2 second delay between the moment the motion event arrives and the moment the appliance module is activated as shown by the following trace:
 
 
Feb 14 07:55:44 ha01 perl[7174]: 2017-02-14 07:55:44 PLCChangeUpdate: house=C, unit=7, status=1
Feb 14 07:55:46 ha01 perl[7174]: 2017-02-14 07:55:46 PLCChangeUpdate: house=B, unit=1, status=1

Feb 14 07:55:47 ha01 perl[7174]: 2017-02-14 07:55:47 PLCChangeUpdate: house=C, unit=7, status=1
Feb 14 07:55:49 ha01 perl[7174]: 2017-02-14 07:55:49 PLCChangeUpdate: house=B, unit=1, status=1

Feb 14 07:56:07 ha01 perl[7174]: 2017-02-14 07:56:07 PLCChangeUpdate: house=C, unit=7, status=1
Feb 14 07:56:09 ha01 perl[7174]: 2017-02-14 07:56:09 PLCChangeUpdate: house=B, unit=1, status=1

Feb 14 07:56:21 ha01 perl[7174]: 2017-02-14 07:56:21 PLCChangeUpdate: house=C, unit=7, status=1
Feb 14 07:56:23 ha01 perl[7174]: 2017-02-14 07:56:23 PLCChangeUpdate: house=B, unit=1, status=1

Feb 14 07:56:40 ha01 perl[7174]: 2017-02-14 07:56:40 PLCChangeUpdate: house=C, unit=7, status=1
Feb 14 07:56:41 ha01 perl[7174]: 2017-02-14 07:56:41 PLCChangeUpdate: house=B, unit=1, status=1

Feb 14 08:18:13 ha01 perl[7174]: 2017-02-14 08:18:13 PLCChangeUpdate: house=C, unit=7, status=1
Feb 14 08:18:15 ha01 perl[7174]: 2017-02-14 08:18:15 PLCChangeUpdate: house=B, unit=1, status=1
 
C7 is the motion sensor
B1 is the zwave module
 
 
The rule goes something like:
 
 "whenever light C7 is on then switch light B1 on for 5 seconds"
 
 
Is there a way to reduce the odd latency ?