Specifications

Document 12245 Rev. I Sheet 35 of 39
Units will respond with a message containing the same instruction code and sub-instruction, and a message
body that contains the data in the same format which is used to set the values.
The message body used to set a value contains the same sub-instruction, followed by the data for the new
setting. The format of the data is described in the sections that follow.
Unless an ACK is requested in the instruction byte, there will be no response to a message with this format. It
is recommended that an ACK request be sent with messages with this format, to verify that the unit "heard"
you. If there is no immediate response, then either there was a communication error, or something was wrong
with the message format.
3.10.1 Mute (18 50)
This message is used to turn the output of the SSPA on or off.
This message should be sent with one enumerated value:
30: Turn the output OFF (Mute)
31: Turn the output ON (Un-mute)
When queried, the value of the mute control is returned the same way. Note, however, that this instruction
only returns the setting of the Mute control, and the output may still be off for another reason. Use the Unit
Status message (section 3.13) to determine the true state of the output.
While the output is muted, all bias currents will read 0 Amps, and the Pout reading will fall to its out-of-range
low value. While muted, no Current Faults or Pout Faults will be generated, but they will not be cleared either.
3.10.2 Redundancy Mode (18 51)
This message can be used to control the redundancy mode.
To set the mode, send this message with a single, one-byte parameter:
30: Manual Mode
31: Auto Mode
32: Spare Mode
When using the message to request the current mode setting, the message is sent with no parameters. The
response will contain two one-byte parameters. The first is compatible with older SSPA products, which could
be set only for Auto or Manual mode. It will be 30 for Manual Mode; or 31 for Auto or Spare mode.
The second parameter will indicate the correct mode, with values identical to those used to set the mode.
3.10.3 Gain Control (18 52)
The gain of the SSPA may be controlled using this message. The gain can be set for -20 to 0 dB, in 0.1 dB
increments. 0 dB represents the maximum possible setting of the gain control.
A single signed analog value is sent to or returned from the SSPA, which represents the gain setting in dB.
3.10.4 Unused Parallel Outputs (18 53)
Parallel I/O outputs that are not assigned any function may be independently controlled remotely via Serial
I/O. You may switch the contact to either its normally-open or its normally-closed position.
B
PIO_UNUSED_OUTPUT_CONTROL_Rx
= 30 to leave unchanged (when setting),
31 for Normally Open,
32 for Normally Closed.
These controls only affect outputs that are not assigned to any function; i.e., if you send a control byte to an
output (Rx, x = 1 to 8) which has been assigned to some function with message 17 59, the control byte will be
ignored. These outputs will default to their normally-open state upon power-up if no control message is
issued. Unused output controls are not stored in non-volatile memory.