TIA-530 (1987) relies on EIA(RS)-422/423 and uses a differential signaling on a DB25 - RS232 format - EIA-530 Transmit (and the other signals) use a twisted pair of wires (TD+ & TD-) instead of TD and a ground reference as in RS232 or V.24. This interface is used for HIGH SPEED synchronous protocols. Using a differential signaling allows for higher speeds over long cabling. This standard is applicable for use at data signaling rates in the range from 20,000 to a nominal upper limit of 2,000,000 bits per second. Equipment complying with this standard, however, need not operate over this entire data signaling rate range. They may be designed to operate over a narrower range as appropriate for the specific application. All signals are EIA-422 (balanced) except LL (pin 18), RL (pin 21), and TM (pin 25) which all use EIA-423 (unbalanced).
TIA-530-A (1992) differs slightly by changing pins 6 and 20 to EIA-423 (unbalanced), adding a Ring Indicator (RI) on pin 22 using EIA-423, and grounding pin 23
Pin | Name | Dir | Description | Circuit | Paired with |
---|---|---|---|---|---|
1 | Shield | ||||
2 | TxD | Transmitted Data | BA | 14 | |
3 | RxD | Received Data | BB | 16 | |
4 | RTS | Request To Send | CA | 19 | |
5 | CTS | Clear To Send | CB | 13 | |
6 | DSR * | Data Set Ready | CC | 22 (not paired in TIA-530-A) | |
7 | SGND | Signal Ground | Ground | ||
8 | DCD | Data Carrier Detect | CF | 10 | |
9 | Rtrn Receive Sig. Elmnt Timing | DD | 17 | ||
10 | Rtrn DCD | CF | 8 | ||
11 | Rtrn Transmit Sig. Elmnt Timing | DA | 24 | ||
12 | Rtrn Transmit Sig. Elmnt Timing | DB | 15 | ||
13 | Rtrn CTS | CB | 5 | ||
14 | Rtrn TxD | BA | 2 | ||
15 | ST | Transmit Signal Element Timing | DB | 12 | |
16 | Rtrn RxD | BB | 3 | ||
17 | RT | Receive Signal Element Timing | DD | 9 | |
18 | LL | Local Loopback | LL | Unbal, not paired | |
19 | Rtrn RTS | CA | 4 | ||
20 | DTR * | Data Terminal Ready | CD | 23 (not paired in TIA-530-A) | |
21 | RL | Remote Loopback | RL | Unbal, not paired | |
22 | ** | Rtrn DSR | CC | 6 (not paired in TIA-530-A) | |
23 | *** | Rtrn DTR | CD | 20 (not paired in TIA-530-A) | |
24 | TT | Transmit Signal Element timing | DA | 11 | |
25 | TM | Test Mode | TM | Unbal, not paired |