Section 5
OM6530-C1-00
19 November, 2019
5-5
error bit in the status register will be set. When the output buffer is not empty then the
message available (MAV) bit will be set in the status register.
5.2.9.
IEEE-488 DEADLOCK
If the controller demands a byte of data from the 6530 and the buffer is empty, the 6530
will set the Query Error flag in the Event Status Register.
5.3.
RS-232C INTERFACE
The 6530 has an RS-232C interface which can be connected to a controller or to a simple printer.
The controller (which can be almost any computer with an RS-232C interface) can control the
6530 through a variety of commands that allow setting the instruments operating parameters, and
analyzing the measurements made by the 6530. The simple printer interface can be used to log
any or all of the measurements taken by the 6530 during normal operation.
When using the RS-232C port to remotely control the 6530, either interactively with a terminal
or under computer control, operation is the same as using an IEEE-488 controller connected to
the IEEE-488 port for control, with the following exceptions:
1.
The program message terminator is Carriage Return (0x0D).
2.
There is no SRQ capability when using serial remote control. The status registers still behave
as described in this chapter, but the 6530 serial interface does not have a way to perform
the SRQ function.
3.
There is no direct way to perform IEEE-488 hardware interface functions such as DCL
(Device Clear) or SDC (Selected Device Clear).
Pin
Name
Function
Direction
1
CHG
Chassis Ground
IN/OUT
2
TxD
Transmit Data
IN
3
RxD
Receive Data
OUT
4
RTS
Request To Send
IN
5
CTS
Clear To Send
OUT
6
DSR
Data Set Ready
OUT
7
GND
Signal Ground
IN/OUT
8
DCD
Data Carrier Detect
OUT
20
DTR
Data Terminal Ready
IN
All other pins not used or connected
Table 5-3 : RS232 Pin Designations
The 6530 Teraohm Bridge-Meter is data communication equipment (DCE) so TxD is an
input (the data which the modem is to transmit).
