feat: Support the configuration of slaves to use only dc sync1

[marcfir]

Our problems with #15 come from a wrong DC configuration.
TwinCAT only uses the SYNC1 signal. If we use the same configuration, the slave can go to OP.

I don't know how to read this from the ESI, but it works.

<Dc>
	<OpMode>
		<Name>DcSync500us</Name>
		<Desc>DC-Synchron (Sync0Shift 500us)</Desc>
		<AssignActivate>#x0500</AssignActivate>
		<CycleTimeSync0 Factor="1">0</CycleTimeSync0>
		<ShiftTimeSync0>500000</ShiftTimeSync0>
	</OpMode>
	<OpMode>
		<Name>DcSync250us</Name>
		<Desc>DC-Synchron (Sync0Shift 250us)</Desc>
		<AssignActivate>#x0500</AssignActivate>
		<CycleTimeSync0 Factor="1">0</CycleTimeSync0>
		<ShiftTimeSync0>250000</ShiftTimeSync0>
	</OpMode>
	<OpMode>
		<Name>DcSync1000us</Name>
		<Desc>DC-Synchron (Sync0Shift 1000us)</Desc>
		<AssignActivate>#x0500</AssignActivate>
		<CycleTimeSync0 Factor="1">0</CycleTimeSync0>
		<ShiftTimeSync0>1000000</ShiftTimeSync0>
	</OpMode>
	<OpMode>
		<Name>FreeRun</Name>
		<Desc>Free Run (no synchronization)</Desc>
		<AssignActivate>#x0000</AssignActivate>
	</OpMode>
</Dc>

[marcfir]

The magic number is <AssignActivate>#x0500</AssignActivate>. This is the Dc active flag. At least the top two bytes.
So when configuring from an ESI file, it may make sense to write the active flag directly instead of the enum number in ec_slave_set_dc_config().

[robert-burger]

ok it understand but did not see that configuration so far.

the "AssignActivate" is simply the content written to register 0x981 (activation register, byte swapped in XML).

Bit 0 : sync activation
Bit 1 : sync0 generation
Bit 2 : sync1 generation

I totally have no idea why they preferred sync 1 generation over sync 0, but obviously they did. Regarding your last comment, can you make the changes to pass the register content directly in ec_slave_set_dc_config? maybe also rename slv.dc.type to slv.dc.activation_reg?

[robert-burger]

write activation reg directly

[marcfir]

Hello Robert. I have added the changes. Does that fit?

[robert-burger]

Lgtm. Very nice, thanks.