Omron LCM100 manual Initial Operation, Fuses, Troubleshooting Technique

DATA-LINC GROUP

LCM100 User’s Guide

Note: If a three-to-two-wire adapter is used to connect to a two-wire AC outlet, the ground lead of the adapter must be connected to earth ground to complete the ground system. An open ground connection may cause a communications defect and/or shock hazard.

Line conditioners in the form of isolators, regulators and surge protectors may be present in the computer system in order to provide clean power, especially on non-dedicated lines. The LCM100 has integral surge protection.

Note: The LCM100 should not be plugged into isolator or surge protector devices as this may cause signal degradation. If Detect indicators do not illuminate with both units connected to line power, a coupling capacitor may be required for cross-phase communication (see appendix B).

Initial Operation

The LCM100 is completely transparent. This means that once the system is correctly installed, it will not be apparent to the system. Like a cable, it requires no attention other than a reliable connection.

With the modules connected to their respective equipment as previously described, ensure that both module’s, Detect and Power indicators are illuminated. Data transfer will occur in both directions as commanded by the interconnected equipment.

Sometimes a random glitch on power lines will cause erroneous data characters to appear at either end of the communications line. This is to be expected, especially during periods when the equipment is idle. Error correction procedures appropriate to your computer operating system can be taken to remove the spuratic characters.

Troubleshooting

The following are methods of eliminating the cause of communication difficulties, which may occur with the LCM100.

Fuses

Each module has a fuse located internally. Replace only with a fuse of similar rating of ½ amp 3 AG.

Troubleshooting Technique

If communication difficulties are encountered, first check for proper cable connections at the power receptacles, and at both RS-232C interface cables. An indication of faulty FSK communication between modules is a missing Detect indicator at either module. An indication of faulty power line connection is the missing power indicator at either module.

To isolate a communications problem from the RS-232C interface, simply connect the equipment directly, without going through the LCM100 modules. If the problem persists, then the defect probably lies within the equipment and not the LCM100.

To isolate line carrier problems from the power distribution circuits, connect each module’s power receptacle into a common power distribution circuit—for example, at the same outlet or through an extension cord. If communications occur at one outlet, but not at another, then the problem is probably due to lack of coupling between phases.

Note: The LCM100 does not use the handshake lines; therefore, communication protocol codes will possibly need to be implemented in order for the LCM100 to operate effectively.

PN 161-09998-001A 3