Blinking red LED; C&K MD's

[chasbo@xxxxxxxxx]

Taking over old system containing C&K  DT435 and DT460S motion
detectors.  Installed NX8E and connected the MD's.

PROBLEM:  Red LED's on all of the MD's blink continuously every second
or so.  Why? Pulsing continues long after power-up. Have powered
down/up several times.

Yellow and green LED's cycle on and off as their respective
technologies are tripped, indicating to me that neither pir nor
microwave have gone to sleep. Red LED's light after yellow and green
LED's light, causing normal relay transfer.  All appears to be normal
except that after the MD's reset, the red LED continues to flash every
second or so, and never stop. System keypad green ready light
extinguishes when there is movement, and lights when the MD's reset.
indicating MD relays are functioning properly.

I have read the 435 manual (do not have a 460S manual), but I did not
see an explanation for the pulsing red LED.  Red LED's continue
pulsing long after power-up.

Brought two 640S to shop workbench.  Applied 12 volt battery, without
charger. No pulsing red LED, even during power-up.  All LED's operate
properly. Units perform perfectly.

Anyone have an answer?