Batboard

Hi Folks,
I've seen where a couple of you have had success in establishing a V.24 link between a DIU and Quantar using a Juniper CTP. I'm trying to achieve this in my lab, but haven't had any success yet. I don't think it's a hardware issue - if I connect to the V.24 port of the Quad connector on the COMM port of the DIU I can link directly to the Quantar. I am using a DB-25 to RJ-45 connector with these pin-outs for the DIU:

DIU-->DB-25------------>Quantar
2-->6 (TXD) ------------>5 (RXD)
3-->5 (RXD) <------------6 (TXD)
7-->4 (GND) ------------>4 (GND)
17->1 (RCLK) <-----------3 (TCLK)
24->3 (TCLK) ----------->1 (RCLK)
4-->8 (RTS) <-------------7 (CTS)
8-->2 (CD) -------------->2 (CD)
5-->7 (CTS) ------------->8 (RTS)

The DIU and Quantar are both programmed for Internal clock. The CTP1002 on the DIU end is set for port speed of 9.6k, RS-232/DCE/NRZ, Configured rate w/o user clk (TT)
The quantar is programmed identically except for the port is Adaptive rate w/o user clk (TT). The DIU IP is 192.168.100.1 and the Quantar is 192.168.100.2 - the ethernet connections are plugged into a simple switch and I have verified that the local and remote bundles point to one another (both use port 1 of the CTP 1002). The packet size is set to 32, and the min, and the min, packet set, and max are 5, 30 and 45, respectively. I orignally tried routing the CTPs together with a CISCO router, but I thought I'd break it down more simple just to verify the link - then add other devices (switch, router, firewall, etc.) The status shows "running" for both CTPs, but no link.......any ideas?

Afternoon Spiderman,

You will have to tie RTS or CTS to ground or themselves depending on how the juniper unit handles the level shifts.

I typically tie the Quantar side but both sides may need it

Best way to try this is with a 8p8c telco banjo and a gator clip jumper.

If the RTS is not activated then there will not be any comms traffic started between the ends

If you have any grade of o-scope you can probe the TX and Rx data lines to see the square wave pulses turn into a data stream once the link is up as you try the jumper

If you are using DB25 to RJ45 adapters for the juniper cables, you need to tie pins 4 and 20 together to so the same thing

You can do this inside of the adapters as is done by most

Thanks for the info!

Ground is not a valid V.24/RS-232 level, control lead "on" is something more than +3V. The best way to treat the Quantar and DIU is to use their own RTS output to hold the CTS and CD inputs on. So break out pins 2,7, and 8 on the RJ45 at the Quantar and tie them together. Same at the DIU.

This means there are only four active lines (TXD, RXD, TCLK, RCLK) that need to be run between units. Using Cat5 you can run each line as half of a twisted pair with a ground on the other half of the pair for best noise immunity on longer runs.

I'm not familiar with Juniper but with Cisco the quick way to get going is to take the CD or DSR output from the router and use it to drive RTS and DTR back into the router serial port when the router port is set in DCE mode.