User's Manual

PMAC VME Hardware Reference Manual

22 PMAC VME Connector Pinouts

J4 JRS422 (26-Pin Connector)

Front View

Pin # Symbol Function Description Notes

1 CHASSI Common PMAC Common

2 S+5V Output +5VDC Supply Deactivated by E8

3 RD- Input Receive Data Diff. I/O low true **

4 RD+ Input Receive Data Diff. I/O high true *

5 SD- Output Send Data Diff. I/O low true **

6 SD+ Output Send Data Diff. I/O high true *

7 CS+ Input Clear to Send Diff. I/O high true **

8 CS- Input Clear to Send Diff. I/O low true *

9 RS+ Output Request to Send Diff. I/O high true **

10 RS- Output Request to Send Diff. I/O low true *

11 DTR Bidirectional Data Terminal Ready Tied to DSR

12 INIT/ Input PMAC Reset Low is Reset

13 GND Common PMAC Common Low is Reset

14 DSR Bidirectional Data Set Ready Tied to DSR

15 SDIO- Bidirectional Special DATA Diff. I/O low true

16 SDIO+ Bidirectional Special Data Diff. I/O high true

17 SCIO- Bidirectional Special CTRL. Diff. I/O low true

18 SCIO+ Bidirectional Special CTRL. Diff. I/O high true

19 SCK- Bidirectional Special Clock Diff. I/O low true

20 SCK+ Bidirectional Special Clock Diff. I/O high true

21 SERVO- Bidirectional Servo Clock Diff. I/O low true ***

22 SERVO+ Bidirectional Servo Clock Diff. I/O high true ***

23 PHASE- Bidirectional Phase Clock Diff. I/O low true ***

24 PHASE+ Bidirectional Phase Clock Diff. I/O high true ***

25 GND Common PMAC Common

26 +5V Output +5VDC Supply Power supply out

The JRS422 connector provides the PMAC with the ability to communicate both in RS422 and RS232. In

addition, this connector is used to daisy chain interconnect multiple PMACs for synchronized operation.

* Note: Required for communications to an RS-422 host port

** Note: Required for communications to an RS-422 or RS-232 host port

*** Note: Output on card @0; input on other cards. These pins are for synchronizing multiple PMACs together

by sharing their phasing and servo clocks. The PMAC designated as card 0 (@0) by its jumpers E40-E43 outputs

its clock signals. Other PMACs designated as cards 1-15 (@1-@F) by their jumpers E40-E43 take these signals

as inputs. If synchronization is desired, these lines should be connected even if serial communications is not used.