How many E-sensor8 and E-opto16 expansion units could be attached to one securityProbe-5E?
First, you could attach the AKCP expansion units to the 4 RJ-45 expansion ports of securityProbe-5E. If you want to attach further E-sensor8 and E-opto16 units, you could chain them together with CAT5 cable. Actually there is no limitation of connected AKCP expansion modules.
Important is, that securityProbe-5E supports in total up to 600 sensors, no matter how many sensors are attached to each expansion module.