I was hoping to use a SDG1010 at work to generate a nice slow square wave as an in input to my test however when I go below around 5Hz, (5Vpp 2.5Voffset), I get multiple edges at the transition which my test will pick up as it is happy with at least 100Hz input.
What spec would I be looking at in the datasheet to check if this is within normal operation? link to datasheet
Is this type of output expected at low frequencies when running the output as a square wave?
How old is yout SDG1010?
On some older units there may exist some higher level glitches just before rising start corner and just before start of falling edge corner.
In some older units there was more these. Later this was solved (it is HW thing)
Later this problem was solved and these glitches pekaks reduced typically under 10% of level and also time before corner where they exist was reduced.
This problem exist only in low frequencies SQUARE wave function. Square wave is derived from internal sinewave (system generates example 5Hz sinewave internally and then use harware PECL comparator for make square from sine. This have advantages and disadvantages. In some older units PECL comparator hysteresis window was too narrow. Also in some cases internal sinewave need bit more filtering before PECL due to system generated and natural noise.
If it is old unit and have this special HW "problem", there is available knowledge how to make it bit better. (need SMD resistor/capacitor rework)
If it is new unit what works normally there is still these some small clitches and if your system is sensitive enough for detect these and you want go over this problem, look where is your system treshold for detect/count pulses and can you rise this treshold so it is near half of level. Normal digital logick system tresholds for 1 or 0 are well defined in data books. If build some equipment these definitions are not wise to break.
Simpest "solution" in practice for generate better (more clean) low frequency square waves with SDG1010 is:
Do not use Square function!
Use Pulse function for generate Square waves. there you can also set 50% duty so it is square wave. (or of course other dyty % or pulse width)
With higher frequencies (I mean example hundreds of kHz or MHz range) Square give better result if look signal cycle to cycle time jitter. (Pulse mode have system 8ns jitter)