Synchronous EIA-232-E Null Modems

Use the cable shown in Figure B-6 to create a direct synchronous connection between two hosts when both sides provide a clock signal:

Figure B-6 Synchronous EIA-232 Null Modem (both sides provide clock)

Use the cable shown in Figure B-7 to create a direct synchronous connection between two hosts when only one side provides a clock signal:

Figure B-7 Synchronous EIA-232 Null Modem (one side supplies clock)