Agilent Technologies 8453 Operator's Manual page 156

WAR NI N G
External Communication
This section gives the definition of the connections to the computer and
peripherals of the spectrophotometer. Connectors with pin assignments and
cables are described in detail.
Only use cables supplied by Agilent Technologies to make sure the
instrument functions properly and complies with safety or EMC
regulations.
The signal levels are defined as:
• standard TTL levels (0 V is logic true, + 5 V is false)
• Input load is 2.2 kOhm against + 5 V
Output are open collector type, inputs/outputs (wired-or technique).
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