About Null or Not Null serial cable

Denis

HI

Sorry for this stupid question about serial cable but I'm confused.

Wish cable I have to use between my PC and NIxxxx controler, Null or not Null?

If I build this cable, I have to cross pin 2 &3 or I do a straight cable?

Thanks in advance

Joe Hebert

You need a null modem (crossed) cable between a PC and a Netlinx NI-xxxx master:

PC

---

Netlinx Master
2<

---

>3
3<

---

>2
5<

---

>5

Denis

Tank you Joe it's appreciate

Impaqt

A Pretty reliable Rule of Thumb is

Same connectors on Both Sides = Null

Opposite connetors = Straight throughThere are exceptions to any "Rule" but this is probobly 90-95% accurate.(Marantz...... Grrrrr.....)

annuello

Sorry, but I'd have to disagree. I've found that the gender is NO indication of whether you should use a cross over or not. I wish that the whole industry would adhere to such a standard, however they don't. Experience has tought me that you should ALWAYS check the documentation rather than hope.

Having said that, I've built a little inline adaptor, D9f to D9m. The Tx & Rx lines run through a DPDT switch, so at the flick of a switch I can cross & un-cross a null/not-null cable. I found it very useful for work in the field.

2 -------0          0          0-----+
         |          +---------------------------- 2
         +-----------------+         |
                           |         |
                    +---------------------------- 3
3 -------0          0      +---0     |
         +---------------------------+

5 ----------------------------------------------- 5

Roger.