Reading control point does not work on old firmware

[alexrudd2]

_read
    await self._init_task
  File "/Users/a.ruddick/Documents/github/alicat/alicat/driver.py", line 314, in _init_control_point
    self.control_point = await self._get_control_point()
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/a.ruddick/Documents/github/alicat/alicat/driver.py", line 479, in _get_control_point
    raise ValueError(f"Unexpected register value: {value:d}") from None
ValueError: Unexpected register value: 4

S/N 105527

firmware 4v25

[alexrudd2]

@BENETNATH had posted:

Same here ? Any solution to drive older firmware ?

[alexrudd2]

Same here ? Any solution to drive older firmware ?

(Development has moved to this fork)

Sadly, no. The explicit command to read the loop variable (LV) was added in firmware version 9. This code uses a direct read of Register 122 in order to work on firmware <9, but I don't know what the earliest possible version is.

@BENETNATH I recommend either

1. removing the code to check/set the "control point" / "loop variable" and hoping the rest works.

2. contacting Alicat support with your serial number - it may be possible to upgrade your unit.

[alexrudd2]

See also numat#28, in particular numat#28 (comment)