Specifications

CI-1 Installation and Operation
P/N 66104700001 Rev. F 1-7
3. Adequate ventilation to remain within the operating temperature and humidity specifications.
Careful site selection is essential prior to installation. Ensure that your site meets all the following
requirements:
1. Within 2000 ft of each ACU (distance measured in cable length).
2. Within 25 ft of the RS-232 host interface.
3. A minimum of 6 ft (2 m) from high voltage or high power equipment.
4. A minimum of 3 ft (1 m) from telephone cabling or equipment.
5. Free from all corrosive fumes and vapors. (Backup batteries should not be stored in the same
cabinet as the ACU and power supply.)
TROUBLESHOOTING
This section provides troubleshooting procedures for CI-1 installations.
POOR OR NO COMMUNICATION
If there is poor or no communication between the host system and the ACUs, do the following:
1. Check connections from the CI-1 to the power supply.
2. Measure the voltage between the CT and AC terminals on the CI-1. It should be between
16 and 20 V; if it is not, replace the transformer or power supply. (The 3708 supplies 400 Hz,
square wave power which may not be read correctly by some voltmeters.)
3. Check that the host computer and ACUs are set to the same baud rates. Check the port
assignment on the host. See the appropriate user's manual.
4. Make sure that a null modem cable is used between the host system and the CI-1.
5. Check all fuses. Replace as necessary.
2. Check that the correct wire type has been used for the 20mA loop connections. Check for
correct wiring; TX- and TX+ should use one twisted pair, RX- and RX+ should use the other
twisted pair. See Figures 1-6 and 1-7.