Measurement Computing Serial488A - Manual (Page 4)

1.2
1.2 Serial488 and Serial488A Differences
The Serial488A is both a hardware and firmware upgrade to the Serial488.
When issuing product improvements, we try to maintain transparent compatibility.
Occasionally this is not possible. You should note the following differences between
the two products.
1. The Serial488 allocated fixed serial and IEEE input buffers of 4000
characters. The Serial488A utilizes a 32,000 character buffer which is
dynamically allocated to the serial and IEEE input buffers as required.
Refer to Section 4.2 for more details
2. The Serial488A has the ability to output RS-232 or RS-422 levels. The
levels used are internally selectable. Refer to Section 2.8 for details.
3. As a peripheral, the Serial488A's serial poll status byte has been
changed to include status of the serial handshake. Other minor changes
have also been included. Refer to Section 4.4 for a complete description
of the serial poll status byte.
4. The internal switch settings for baud rate have been adjusted to include
57600 baud. Refer to Section 2.3 for the new switch settings.
1.3 Serial488A, Serial488A/OEM and Serial488/512K Differences
1. The Serial488A and Serial488A/OEM utilize a 32,000 character buffer
which is dynamically allocated to the serial and IEEE input buffers as required. The
Serial488/512K utilizes a 512,000 character buffer which is dynamically allocated to
the serial and IEEE input buffers as required.
2. The Serial488A and Serial488A/OEM have the ability to output RS-232 or
RS-422 levels. The Serial488/512K can only operate at RS-232 levels.
3. The Serial488A and Serial488A/OEM can operate at selectable baud rates
up to 57600 baud. The Serial488/512K can operate at selectable baud rates up to
19200 baud.