Null Modem Cable CB-NM-xxx-xxx-xx Null Modem serial cables allows two DTE (computer, terminal, printer, etc...) or DCE (i.e. modems ...) devices to communicate with no conflict in data transmission. The transmit and receive signals are crossed to ensure proper data transmission. Cables in male-to-female configurations are typically used as serial printer cables, while female-to-female versions are typically connecting two PC serial ports. With a null modem connection the transmit and receive lines are crosslinked. Depending on the purpose, sometimes also one or more handshake lines are crosslinked. Several wiring layouts are in use because the null modem connection is not covered by a standard. a.      b.      c.      d. e.      f.      g. Options: a. DB9 (D-Sub 9-pin) Female to DB9 (D-Sub 9-pin) to Female       1. CB-NM-9DBF-9DBF-06 -   6-foot Null Modem Cable       2. CB-NM-9DBF-9DBF-10 - 10-foot Null Modem Cable       3. CB-NM-9DBF-9DBF-15 - 15-foot Null Modem Cable       4. CB-NM-9DBF-9DBF-25 - 25-foot Null Modem Cable b. DB9 (D-Sub 9-pin) Female to DB9 (D-Sub 9-pin) to Male       5. CB-NM-9DBF-9DBM-06 -   6-foot Null Modem Cable       6. CB-NM-9DBF-9DBM-10 - 10-foot Null Modem Cable       7. CB-NM-9DBF-9DBM-15 - 15-foot Null Modem Cable       8. CB-NM-9DBF-9DBM-25 - 25-foot Null Modem Cable c. DB9 (D-Sub 9-pin) Female to DB25 (D-Sub 25-pin) to Female       9. CB-NM-9DBF-25DBF-06 -   6-foot Null Modem Cable     10. CB-NM-9DBF-25DBF-10 - 10-foot Null Modem Cable     11. CB-NM-9DBF-25DBF-15 - 15-foot Null Modem Cable     12. CB-NM-9DBF-25DBF-25 - 25-foot Null Modem Cable d. DB9 (D-Sub 9-pin) Female to DB25 (D-Sub 25-pin) to Male     13. CB-NM-9DBF-25DBM-06 -   6-foot Null Modem Cable     14. CB-NM-9DBF-25DBM-10 - 10-foot Null Modem Cable     15. CB-NM-9DBF-25DBM-15 - 15-foot Null Modem Cable     16. CB-NM-9DBF-25DBM-25 - 25-foot Null Modem Cable e. DB25 (D-Sub 25-pin) Female to DB25 (D-Sub 25-pin) to Female     17. CB-NM-25DBF-25DBF-06 -   6-foot Null Modem Cable     18. CB-NM-25DBF-25DBF-10 - 10-foot Null Modem Cable     19. CB-NM-25DBF-25DBF-15 - 15-foot Null Modem Cable     20. CB-NM-25DBF-25DBF-25 - 25-foot Null Modem Cable f. DB25 (D-Sub 25-pin) Female to DB25 (D-Sub 25-pin) to Male     21. CB-NM-25DBF-25DBM-06 -   6-foot Null Modem Cable     22. CB-NM-25DBF-25DBM-10 - 10-foot Null Modem Cable      23. CB-NM-25DBF-25DBM-15 - 15-foot Null Modem Cable     24. CB-NM-25DBF-25DBM-25 - 25-foot Null Modem Cable  g. DB25 (D-Sub 25-pin) Male to DB25 (D-Sub 25-pin) to Male     25. CB-NM-25DBM-25DBM-06 -   6-foot Null Modem Cable     26. CB-NM-25DBM-25DBM-10 - 10-foot Null Modem Cable     27. CB-NM-25DBM-25DBM-15 - 15-foot Null Modem Cable     28. CB-NM-25DBM-25DBM-25 - 20-foot Null Modem Cable Note: (not all items are available for purchase, subject to inventory)